US20200318706A1 - Damper - Google Patents
Damper Download PDFInfo
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- US20200318706A1 US20200318706A1 US16/769,629 US201816769629A US2020318706A1 US 20200318706 A1 US20200318706 A1 US 20200318706A1 US 201816769629 A US201816769629 A US 201816769629A US 2020318706 A1 US2020318706 A1 US 2020318706A1
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- Prior art keywords
- holding chamber
- fluid holding
- peripheral surface
- inner peripheral
- outer peripheral
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
- F16F9/14—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
- F16F9/14—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect
- F16F9/16—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts
- F16F9/18—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts with a closed cylinder and a piston separating two or more working spaces therein
- F16F9/20—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts with a closed cylinder and a piston separating two or more working spaces therein with the piston-rod extending through both ends of the cylinder, e.g. constant-volume dampers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
- F16F9/14—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect
- F16F9/145—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only rotary movement of the effective parts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
- F16F9/34—Special valve constructions; Shape or construction of throttling passages
- F16F9/3405—Throttling passages in or on piston body, e.g. slots
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
- F16F9/36—Special sealings, including sealings or guides for piston-rods
- F16F9/362—Combination of sealing and guide arrangements for piston rods
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
- F16F9/36—Special sealings, including sealings or guides for piston-rods
- F16F9/369—Sealings for elements other than pistons or piston rods, e.g. valves
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2202/00—Indexing codes relating to the type of spring, damper or actuator
- B60G2202/20—Type of damper
- B60G2202/22—Rotary Damper
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F2224/00—Materials; Material properties
- F16F2224/02—Materials; Material properties solids
- F16F2224/025—Elastomers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F2230/00—Purpose; Design features
- F16F2230/30—Sealing arrangements
Definitions
- the present invention relates to a damper that limits the movement of viscous fluid to apply a damping force in reaction to an external force.
- a known damper gives a damping force in reaction to an external force by limiting a movement of a viscous fluid.
- This type of damper has a fluid holding chamber having opening sections and holding the viscous fluid, a resistance generating member partitioning an inside of the fluid holding chamber and inserted in the opening sections of the fluid holding chamber so as to move or rotate relative to the fluid holding chamber by receiving the external force, volume changing means partitioning the inside of the fluid holding chamber and capable of compressing one area and expanding another area within the partitioned fluid holding chamber according to the movement or the rotation of the resistance generating member relative to the fluid holding chamber, and a flow passage connecting between the areas within the fluid holding chamber partitioned by the volume changing means.
- the Patent Literature 1 discloses a rotary damper for generating a damping torque in reaction to an applied rotation force by limiting the movement of a viscous fluid.
- This rotary damper has a housing having an inner chamber with one end opened, a rotor housed within the inner chamber of the housing, the viscous fluid (fluid substance) filled within the inner chamber of the housing, and a plug attached to an opening side end of the housing so as to seal in the viscous fluid filled within the inner chamber of the housing.
- the housing and the plug together form the fluid holding chamber.
- the rotor has a rotor body in a substantial circular cylinder shape and movable vanes projecting radially outward from an outer peripheral surface of the rotor body toward an inner peripheral surface of the inner chamber of the housing.
- the rotor body corresponds to the resistance generating member.
- Fixed vanes are formed on the inner peripheral surface of the inner chamber of the housing, each projecting radially inward toward an outer peripheral surface of the rotor body to partition the inner chamber of the housing.
- Flow passages i.e. orifices are formed through the respective fixed vanes of the housing so as to connect between the respective areas into which the inner chamber of the housing is partitioned by the respective fixed vanes.
- a bottom of the inner chamber of the housing and the plug each include a through-hole for rotatable insertion of a corresponding end part of the rotor body. These through-holes correspond the opening sections of the fluid holding chamber.
- One end part of the rotor body is inserted into the through-hole formed in the bottom of the inner chamber of the housing, another end part of the rotor body is inserted into the through-hole formed in the plug, and the rotor is thereby housed within the inner chamber of the housing so as to be rotatable relative to this inner chamber.
- each of the movable vanes compresses the area located upstream in a rotor rotation direction from the corresponding fixed vane of the inner chamber and a pressure on the viscous fluid in this area is increased. This causes the viscous fluid in this area to pass through the flow passage formed in the corresponding fixed vane and to moves to the area located downstream in the rotor rotation direction from the corresponding fixed vane of the inner chamber. At this time, the damping torque generates depending on a resistance to motion of the viscous fluid (the degree to which the viscous fluid is hard to be moved through the flow passage).
- Patent Literature 1 Japanese Unexamined Patent Application Laid-Open No. 2014-005883
- an O-ring made of an elastic body such as rubber is arranged between each opening section of the fluid holding chamber and the resistance generating member inserted in this opening section in order to prevent leakage of the viscous fluid held in the fluid holding chamber through a gap therebetween. Therefore, the following may occurs.
- the external force applied to the resistance generating member deforms the O-ring elastically to deviate a center axis of the resistance generating member from a center axis of the fluid holding chamber, thus causing misalignment.
- stiffness of the O-ring is to be enhanced. Enhancement of the stiffness of the O-ring may, however, cause the O-ring to resist elastic deformation depending on the movement or the rotation of the resistance generating member and then generate a gap between the resistance generating member and the O-ring, thus resulting in leakage of the viscous fluid held in the fluid holding chamber through this gap.
- the O-ring since having a circular cross-section, varies in respective contact areas between it and the resistance generating member and between it and the opening section of the fluid holding chamber when it is elastically deformed in its radial direction. This may lead to instability of a seal between the resistance generating member and the opening section of the fluid holding chamber, thus further increasing the likelihood of external leakage of the viscous fluid held in the fluid holding chamber through the gap therebetween.
- the present invention has been made in view of the above situation, and an object of the invention is to provide a damper capable of ensuring against the leakage of the viscous fluid held in the fluid holding chamber.
- a bushing is attached to an opening section of a fluid holding chamber so that a resistance generating member is slidably held by this bushing, and an elastic member in an annular shape is located between the resistance generating member held by this bushing and the opening section of the fluid holding chamber and has the following: an outer peripheral surface having a width in a direction of a center axis of the fluid holding chamber and being pressed against the fluid holding chamber; and an inner peripheral surface having a width in the direction of the center axis of the fluid holding chamber and being pressed against the resistance generating member.
- the present invention provides a damper for generating a damping force in reaction to an external force by limiting a movement of a viscous fluid
- the damper includes the following:
- a fluid holding chamber having the opening section and holding the viscous fluid within
- a resistance generating member inserted in the opening section of the fluid holding chamber and movable relative to the fluid holding chamber in reaction to the external force;
- volume changing means partitioning an inside of the fluid holding chamber and configured to compress one of areas within the fluid holding chamber partitioned and expand another of the areas, with a movement of the resistance generating member relative to the fluid holding chamber;
- the elastic member includes the following:
- the bushing attached to the opening section of the fluid holding chamber holds the resistance generating member slidable, therefore resulting in reduction of a misalignment of the resistance generating member even without enhancement of stiffness of the elastic member.
- the elastic member in an annular shape which includes the inner peripheral surface and the outer peripheral surface each having the width in the direction of the center axis of the fluid holding chamber, is located between the resistance generating member held by bushing and the opening section of the fluid holding chamber.
- FIGS. 1(A) to 1(C) are respectively a front view, a side view, and a back view, of a rotary damper 1 according to one embodiment of the present invention.
- FIG. 2(A) is an A-A cross-section view of the rotary damper 1 as illustrated in FIG. 1(A)
- FIG. 2(B) is a B-B cross-section view of the rotary damper 1 as illustrated in FIG. 1(B) .
- FIG. 3(A) and FIG. 3(B) are respectively an enlarged view of the part A and an enlarged view of the part B, of the rotary damper 1 as illustrated FIG. 2(A) .
- FIG. 4(A) is an enlarged view of the part C of the rotary damper 1 as illustrated FIG. 2(A)
- FIG. 4(B) is an enlarged view of the part D of the rotary damper 1 as illustrated in FIG. 2(B) .
- FIG. 5(A) is a front view of a case 2
- FIG. 5(B) is a C-C cross-section view of the case 2 as illustrated in FIG. 5(A)
- FIG. 5(C) is a back view of the case 2 .
- FIG. 6(A) and FIG. 6(B) are respectively a front view and a side view, of a rotor 3
- FIG. 6(C) is a D-D cross-section view of the rotor 3 as illustrated in FIG. 6(A) .
- FIG. 7(A) and FIG. 7(B) are respectively a side view and a front view, of each of the first and second bushings 4 a , 4 b
- FIG. 7(C) is an E-E cross-section view of each of the first and second bushings 4 a , 4 b as illustrated in FIG. 7(B) .
- FIG. 8(A) and FIG. 8(B) are respectively a front view and a side view, of a valve seal 5
- FIG. 8(C) is an F-F cross-section view of the valve seal 5 as illustrated in FIG. 8(A) .
- FIGS. 9(A) to 9(C) are a front view, a side view, and a back view, of a lid 6
- FIG. 9(D) is a G-G cross-section view of the lid 6 as illustrated in FIG. 9(A) .
- FIG. 10(A) is a front view of each of the first and second sealing rings 8 a , 8 b
- FIG. 10(B) is an H-H cross-section view of each of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10(A)
- FIG. 10(C) is an enlarged view of the part E of each of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10(A)
- FIG. 10(D) is an enlarged view of the part F of each of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10(B) .
- FIG. 11(A) is a front view of each of modifications 8 ′ a , 8 ′ b of the first and second sealing rings 8 a , 8 b
- FIG. 11(B) is an I-I cross-section view of each modification 8 ′ a , 8 ′ b as illustrated in FIG. 11(A)
- FIG. 11(C) is an enlarged view of the part G of each modification 8 ′ a , 8 ′ b as illustrated in FIG. 11(B) .
- FIG. 12(A) is a side view of a linear type damper 9 according to another embodiment of the present invention
- FIG. 12(B) is a J-J cross-section view of the linear type damper as illustrated in FIG. 12(A) .
- FIGS. 1(A) to 1(C) are respectively a front view, a side view, and a back view, of a rotary damper 1 according to the embodiment of the present invention.
- FIG. 2(A) is an A-A cross-section view of the rotary damper 1 as illustrated in FIG. 1(A)
- FIG. 2(B) is a B-B cross-section view of the rotary damper 1 as illustrated in FIG. 1(B)
- FIG. 3(A) and FIG. 3(B) are respectively an enlarged view of the part A and an enlarged view of the part B, of the rotary damper 1 as illustrated FIG. 2(A) .
- FIG. 4 (A) is an enlarged view of the part C of the rotary damper 1 as illustrated FIG. 2(A)
- FIG. 4(B) is an enlarged view of the part D of the rotary damper 1 as illustrated in FIG. 2(B) .
- the rotary damper 1 according to the present embodiment can be used for any device in which a rotational motion of a bi-directionally rotatable rotator is to be damped, such as seats with reclining function for use in any apparatuses, for example, automobiles, railroad vehicles, aircrafts, and vessels.
- the rotary damper 1 according to the present embodiment includes the following: a case 2 and a lid 6 that form a fluid holding chamber holding a viscous fluid (not illustrated in the figures), such as oil or silicone; and a rotor 3 housed in the fluid holding chamber so as to be rotatable relative to the fluid holding chamber.
- FIG. 5(A) is a front view of the case 2
- FIG. 5(B) is a C-C cross-section view of the case 2 as illustrated in FIG. 5(A)
- FIG. 5(C) is a back view of the case 2 .
- a circular cylindrical chamber 21 with one end opened i.e. a space having a circular cylindrical shape with a bottom
- a through-hole 23 for insertion of the rotor 3 is formed in a bottom part 22 of this circular cylindrical chamber 21 so as to serve as an opening section of the fluid holding chamber.
- Below-mentioned first sealing ring 8 a and first bushing 4 a are fitted in this through-hole 23 ; a lower end part 33 a of a below-mentioned rotor body 31 (See FIG.
- a step 221 and a step 222 are formed on an inner peripheral surface 220 of the through-hole 23 of the circular cylindrical chamber 21 so as to restrict respectively the first sealing ring 8 a and the first bushing 4 a from moving axially outward (i.e. toward the outside of the case 2 in an axial direction of the rotary damper 1 ).
- a pair of partitioning parts 25 along the center axis 20 of the circular cylindrical chamber 21 is formed on an inner peripheral surface 24 of the circular cylindrical chamber 21 so as to be axisymmetrically with respect to this center axis 20 , and the partitioning parts 25 project radially inward so as to place respective front faces 26 close to an outer peripheral surface 34 of the below-mentioned rotor body 31 (See FIG. 6 ) of the rotor 3 , thereby partitioning an inside of the circular cylindrical chamber 21 .
- an internal threaded section 27 is formed on an opening side 28 of the inner peripheral surface 24 of the circular cylindrical chamber 21 so as to be screwed onto a below-mentioned external threaded section 62 (See FIG. 9 ) of the lid 6 .
- FIG. 6(A) and FIG. 6(B) are respectively a front view and a side view, of the rotor 3
- FIG. 6(C) is a D-D cross-section view of the rotor 3 as illustrated in FIG. 6(A) .
- the rotor 3 includes the rotor body 31 in a cylindrical shape and a pair of vanes (rotor blades) 32 formed axisymmetrically with respect to the rotation axis 30 of the rotor body 31 .
- Each of the vanes 32 is formed along the rotation axis 30 of the rotor 31 and projects radially outward from the outer peripheral surface 34 of the rotor body 3 so as to place a corresponding front face 35 close to the inner peripheral surface 24 of the circular cylindrical chamber 21 inside the case 2 , thereby partitioning the inside of the circular cylindrical chamber 21 .
- the vanes 32 along with the partitioning parts 25 of the circular cylindrical chamber 21 within the case 2 , form volume changing means to compress and expand respectively one area and another area into which the fluid holding chamber is partitioned by the vanes 32 .
- a flow passage 36 is formed in each of the vanes 32 along a rotation direction of the rotor 3 so as to pass through both side faces 37 a , 37 b of the corresponding vane 32 .
- a valve seal 5 is attached to each of the vanes 32 (See FIG. 2(B) and FIG. 4(B) ).
- the rotor body 31 of the rotor 3 works as a resistance generating member capable of rotating relative to the fluid holding chamber in reaction to an external force.
- the lower end part 33 a is to be rotatably inserted into the through-hole 23 formed in the bottom part of the circular cylindrical chamber 21 within the case 2 (See FIG. 2(A) and FIG. 4(A) ) and an upper end part 33 b is to be rotatably inserted into a below-mentioned through-hole (See FIG. 9 ) in the lid 6 (See FIG. 2(A) , FIG. 3(A) , and FIG. 3(B) ).
- the rotor body 31 includes a insertion hole 38 formed with the rotation axis 30 as center so that a shaft with machined double flats (not illustrated in the figures) for transmitting the external rotation force to the rotor 3 is to be inserted into the hole 38 .
- the lower end part 33 a of the rotor body 31 is to be rotatably inserted into below-mentioned first sealing ring 8 a and the first bushing 4 a both attached to the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 (See FIG. 4(A) ).
- a step 340 a is formed on the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31 so as to restrict the first sealing ring 8 a and the first bushing 4 a from moving axially inward (i.e. toward the inside of the case 2 in the axial direction of the rotary damper 1 ).
- the upper end part 33 b of the rotor body 31 whereas, is to be rotatably inserted into a second sealing ring 8 b and a second bushing 4 b both attached to the below-mentioned through-hole 60 in the lid 6 (See FIG. 3(A) and FIG. 3(B) ).
- a step 340 b is formed on the outer peripheral surface 34 of the upper end part 33 b of the rotor body 31 so as to restrict the second sealing ring 8 b and the second bushing 4 b from moving axially inward.
- FIG. 7(A) and FIG. 7(B) are respectively a side view and a front view, of each of the first and second bushings 4 a , 4 b
- FIG. 7(C) is an E-E cross-section view of each of the first and second bushings 4 a , 4 b as illustrated in FIG. 7(B) .
- the first bushing 4 a and the second bushing 4 b are each a cylindrical member made of material excellent in sliding properties: the first bushing 4 a has an inner peripheral surface 40 a slidable relative to the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31 of the rotor 3 and an outer peripheral surface 41 a to abut the inner peripheral surface 220 of the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 , and the second bushing 4 b has an inner peripheral surface 40 b slidable relative to the outer peripheral surface 34 of the upper end part 33 b of the rotor body 31 of the rotor 3 and an outer peripheral surface 41 b to abut an inner peripheral surface 64 of the through-hole 60 in the lid 6 (See FIG. 9(D) ).
- the first bushing 4 a and the second bushing 4 b are each made of metal, such as brass alloy, or synthetic resin, such as PTFE (polytetrafluoroethylene), polyacetal resin, polyethylene resin, polyamide resin, and polyphenylene sulfide resin.
- the first bushing 4 a and the second bushing 4 b may each be made of such multi-layer sliding material in which a plurality of sliding layers are formed on an inner peripheral surface of a backing material, such as cylindrical steel plate or resin composite in a cylindrical shape. Used may be a multi-layer sliding material such that a sintered metallic layer is formed on an inner peripheral surface of a backing material made of a cylindrical steel plate and a sliding resin layer containing PTFE is further formed overlying there, for example.
- FIG. 8(A) and FIG. 8(B) are respectively a front view and a side view, of the valve seal 5
- FIG. 8(C) is an F-F cross-section view of the valve seal 5 as illustrated in FIG. 8(A) .
- each of the valve seals 5 which has a U-shape attachable to the corresponding vane 32 of the rotor 3 , includes a bottom part 50 having a width t2 longer than a rotational directional width t1 (See FIG. 6(A) ) of the corresponding vane 32 , a first branch 53 formed integrally with one edge 51 of the bottom part 50 and having a width t4 longer than a radial directional width t3 (See FIG.
- the valve seals 5 attached to the vanes 32 is each located so as to interpose the bottom part 50 between the front face 35 of the corresponding vane 32 and the inner peripheral surface 24 of the circular cylindrical chamber 21 inside the case 2 , thereby sealing a gap therebetween (See FIG. 4(B) ).
- rotating the rotor 3 in a first rotating direction R1 relative to the circular cylindrical chamber 21 inside the case 2 causes each of the valve seal 5 to bring the first branch 53 into contact with one side face 37 a of the corresponding vane 32 , thereby closing the flow passage 36 formed through each of the vanes 32 .
- each of the valve seals 5 is arranged between the case 2 and the rotor 3 which are rotatable relative to each other, material excellent in sliding properties, for example, synthetic resin, such as polyamide resin, may be preferably used for each the valve seals 5 .
- FIGS. 9(A) to 9(C) are a front view, a side view, and a back view, of the lid 6
- FIG. 9(D) is a G-G cross-section view of the lid 6 as illustrated in FIG. 9(A) .
- the through-hole 60 for insertion of the rotor 3 is formed at a place opposite to the through-hole 23 formed in the bottom part 22 of the circular cylindrical chamber 21 inside the case 2 so as to serve as an opening section of the fluid holding chamber.
- the second sealing ring 8 b and the second bushing 4 b (See FIG. 3(A) ) each being described below, are attached to this through-hole 60 , and the upper end part 33 b of the rotor body 31 of the rotor 3 is to be inserted into the through-hole 60 in which these second sealing ring 8 b and second bushing 4 b are already fitted.
- a step 65 and a step are formed on the inner peripheral surface 64 of the through-hole 60 so as to prevent the second sealing ring 8 b and the second bushing 4 b from moving axially outward, respectively.
- the external threaded section 62 is formed so as to be screwed into the internal threaded section 27 formed on the opening side 28 of the inner peripheral surface 24 of the circular cylindrical chamber 21 , and furthermore a circumferential groove 67 for installation of an O-ring 7 is also formed on the lower face 63 side in relation to the external threaded section 62 .
- the O-ring 7 is installed in the groove 67 and is interposed between the outer peripheral surface 61 of the lid 6 and the inner peripheral surface 24 of the circular cylindrical chamber 21 , thereby preventing the viscous fluid from leaking outside through a threaded engagement section between the external threaded section 62 of the lid 6 and the internal threaded section 27 of the circular cylindrical chamber 21 (See FIG. 3(A) and FIG. 3(B) ).
- FIG. 10(A) is a front view of each of the first and second sealing rings 8 a , 8 b
- FIG. 10(B) is an H-H cross-section view of each of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10(A)
- FIG. 10(C) is an enlarged view of the part E of each of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10(A)
- FIG. 10(D) is an enlarged view of the part F of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10(B) .
- the first sealing ring 8 a and the second sealing ring 8 b are each an annular member made of elastic material, such as nitrile butadiene rubber (NBR): the first sealing ring 8 a has an inner diameter d1 smaller than an outer diameter d4 of the lower end part 33 a of the rotor body 31 of the rotor 3 and an outer diameter d2 larger than an inner diameter (an outer diameter of the step 221 ) d3 of the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 ; and the second sealing ring 8 b has an inner diameter d1 smaller than an outer diameter d5 of the upper end part 33 b of the rotor body 31 of the rotor 3 and an outer diameter d2 larger than an inner diameter (an outer diameter of the step 65 ) d6 of the through-hole 60 in the lid 6 .
- the first sealing ring 8 a and the second sealing ring 8 b each include an inner peripheral annular part 81 rectangular in cross-section
- each ring 8 a , 8 b includes an inner peripheral surface 84 having a width t6 that is flat in a direction of a center axis 80 coincident with the center axis 20 of the circular cylindrical chamber inside the case 2 .
- the first sealing ring 8 a and the second sealing ring 8 b each enable resultant reduction of any change in contact area between the corresponding inner peripheral surface 84 and its counterpart surface upon being elastically deformed in the radial direction because the corresponding inner peripheral surface 84 has the width t6 that is flat in the direction of the center axis 80 .
- the inner peripheral surface 84 of the first sealing ring 8 a is pressed against the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31 of the rotor 3 and that of the second sealing ring 8 b is pressed against the outer peripheral surface 34 of the upper end part 33 b of the rotor body 31 of the rotor 3 .
- a circumferential grease groove 86 is formed in the inner peripheral surface 84 , and grease is filled in this grease groove 86 . It is one circumferential grease groove 86 here that is formed in the inner peripheral surface 84 ; however, a plurality of circumferential grease grooves 86 may be formed in the inner peripheral surface 84 .
- each ring 8 a , 8 b includes an outer peripheral surface 85 having a width t7 that is flat in the direction of the center axis 80 coincident with the center axis 20 of the circular cylindrical chamber 21 inside the case 2 .
- the first sealing ring 8 a and the second sealing ring 8 b each enable resultant reduction of any change in contact area between the corresponding outer peripheral surface 85 and its counterpart surface upon being elastically deformed in the radial direction because the corresponding outer peripheral surface 85 has the width t7 that is flat in the direction of the center axis 80 .
- the outer peripheral surface 85 of the first sealing ring 8 a is pressed against the inner peripheral surface 220 of the through-hole 23 of the circular cylindrical chamber 21 inside the case 2
- that of the second sealing ring 8 b is pressed against the inner peripheral surface 64 of the through-hole 60 in the lid 6 .
- the width t6 of the inner peripheral surface 84 of the inner peripheral annular part 81 is narrower than the width t7 of the outer peripheral surface of the outer peripheral annular part 82 (t6 ⁇ t7). This results in a frictional resistance of the inner peripheral surface 84 of each inner peripheral annular part 81 smaller than a frictional resistance of the outer peripheral surface of the corresponding outer peripheral annular part 82 .
- the ratio of the width t6 of the inner peripheral surface 84 of the corresponding inner peripheral annular part 81 to the width t7 of the outer peripheral surface 85 of the corresponding outer peripheral annular part 82 may be preferably given by t7/t6 ⁇ 3.
- the width t7 of the outer peripheral surface 85 of the outer peripheral annular part 82 is too long compared to the width t6 of the inner peripheral surface 84 of the inner peripheral annular part 81 ; an edge part of the outer peripheral surface 85 of the outer peripheral annular part 82 becomes bent radially inward, and therefore the intended sealablity may not be provided. In addition, this may result in the need for larger installation space for the first sealing ring 8 a or for the second sealing ring 8 b.
- a width t9 of the grease groove 86 provided on the inner peripheral surface 84 of the corresponding inner peripheral annular part 81 may preferably has the following relation to the width t6 of the inner peripheral surface 84 of the corresponding inner peripheral annular part 81 : 0.05 ⁇ t9/t6 ⁇ 0.5.
- the t9/t6 less than 0.05 causes retaining amount of the lubricating grease within the grease groove 86 to decrease, and this may result in sliding performance degradation.
- the t9/t6 greater than 0.5 causes the contact area between the inner peripheral surface of the inner peripheral annular part 81 and the surface (the outer peripheral surface 34 of the lower end part 33 a or the upper end part 33 b of the rotor body 31 of the rotor 3 ) against which the inner peripheral surface 84 is pressed to become too small, and this may result in sealability degradation.
- the coupling part 83 is located between the inner peripheral annular part 81 and the outer peripheral annular part 82 to provide a connection between the two.
- the coupling part 83 has a width t8 (t8 ⁇ t6 ⁇ t7) smaller in the direction of the center axis 80 than both the width t6 of the inner peripheral annular part 81 (the width of the inner peripheral surface 84 ) and the width t7 of the outer peripheral annular part 82 (the width of the outer peripheral surface 85 ).
- first sealing ring 8 a and the second sealing ring 8 b each are subject to a stress, this allows the corresponding coupling part 83 to be deformed elastically so as to absorb the stress, thereby restraining the corresponding inner peripheral annular part and the corresponding outer peripheral annular part 82 from being elastically deformed.
- the ratio of the width t8 of the corresponding coupling part 83 to the width t6 of the corresponding inner peripheral annular part 81 may be preferably given by 0.3 ⁇ t8/t6 ⁇ 0.95.
- the t8/t6 smaller than 0.3 causes stiffness of the corresponding coupling part 83 to decrease, thereby allowing pressing force exerted on the outer peripheral surface 34 of the lower end part 33 a or of the upper end part 33 b of the rotor body 31 of the rotor 3 by the inner peripheral surface 84 of the inner peripheral annular part 81 to become too small, and this may result in sealability degradation.
- the t8/t6 greater than 0.95 causes stiffness of the corresponding coupling part 83 to increase, thereby allowing pressing force exerted on the outer peripheral surface 34 of the lower end part 33 a or of the upper end part 33 b of the rotor body 31 of the rotor 3 by the inner peripheral surface of the inner peripheral annular part 81 to become too strong, and this may results in sliding performance degradation.
- the rotor 3 is slidably held by both of the first bushing 4 a and the second bushing 4 b respectively attached to the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 and the through-hole 60 in the lid 6 , and therefore the misalignment of the rotor 3 is suppressed even without enhancement of the stiffness of the first sealing ring 8 a and the second sealing ring 8 b which along with the first bushing 4 a and the second bushing 4 b hold the rotor 3 slidable.
- first sealing ring 8 a and the second sealing ring 8 b to be each designed to have such low stiffness that the both rings 8 a , 8 b can be elastically deformed depending on the rotation of the rotor 3 , thereby resulting in no gap both between the rotor 3 and the first sealing ring 8 a and between the rotor 3 and the second sealing ring 8 b and in resultant decrease of the likelihood of external leakage of the viscous fluid held in the circular cylindrical chamber 21 inside the case 2 .
- the first sealing ring 8 a is located between the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 and the lower end part 33 a of the rotor body 31 of the rotor 3 , and is an elastic member having the outer and inner peripheral surfaces 85 , 84 , namely, the outer peripheral surface 85 having the width t7 that is flat in the direction of the center axis 20 of the circular cylindrical chamber 21 and being pressed against the inner peripheral surface 220 of the through-hole 23 , and the inner peripheral surface 84 having the width t6 that is flat in the direction of the center axis 20 of the circular cylindrical chamber 21 and being pressed against the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31 ; whereas the second sealing ring 8 b is located between the through-hole 60 in the lid 6 and the upper end part 33 b of the rotor body 31 , and is an elastic member having the outer and inner peripheral surfaces 85 , 84 , namely, the outer peripheral surface 85 having the width
- the width t6 of the inner peripheral surface 84 is smaller than the width t7 of the outer peripheral surface 85 .
- the circumferential grease grooves 86 are formed in the inner peripheral surfaces 84 of the first and second sealing rings 8 a , 8 b , and the grease is filled in these grease grooves 86 . Therefore, frictional resistance between each of the first and second sealing rings 8 a , 8 b and the rotor 3 becomes decreased, and this enables the rotor 3 to slide more smoothly.
- the first and second sealing rings 8 a , 8 b each have the corresponding inner peripheral annular part 81 rectangular in cross section including the inner peripheral surface 84 , the corresponding outer peripheral annular part 82 rectangular in cross section including the outer peripheral surface 85 , and the corresponding coupling part 83 providing the connection between the corresponding inner peripheral annular part 81 and the corresponding outer peripheral annular part 82 ; in addition, the coupling part 83 of each rings 8 a , 8 b has the width t8 which is smaller in the direction of the center axis 20 of the circular cylindrical chamber 21 than that of both the corresponding inner peripheral annular part 81 and the corresponding outer peripheral annular part 82 .
- the corresponding coupling part 82 is elastically deformed to absorb the stress, thereby suppressing elastic deformation of the corresponding inner peripheral annular part 81 and that of the corresponding outer peripheral annular part 82 to reduce the changes in the following respective contact areas: the contact area between the first sealing ring 8 a and the lower end part 33 a of the rotor body 31 , the contact area between the first sealing ring 8 a and the through-hole 23 of the circular cylindrical chamber 21 , the contact area between the second sealing ring 8 b and the upper end part 33 b of the rotor body 31 , and the contact area between the second sealing ring 8 b and the through-hole in the lid 6 .
- the step 221 and the step 222 are formed on the inner peripheral surface 220 of the through-hole 23 of the circular cylindrical chamber inside the case 2 so as to respectively restrict the first sealing ring 8 a and the first bushing 4 a from moving axially outward
- the step 340 a is formed on the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31 so as to restrict the first sealing ring 8 a and the first bushing 4 a , both being attached, from moving axially inward.
- the step 65 and the step 66 are formed on the inner peripheral surface of the through-hole 60 in the lid 6 so as to restrict respectively the second sealing ring 8 b and the second bushing 4 b from moving axially outward
- the step 340 b is formed on the outer peripheral surface 34 of the upper end part 33 b of the rotor body 31 so as to restrict the second sealing ring 8 b and the second bushing 4 b from moving axially inward.
- each of the valve seals 5 acts as a slide bearing for slidable support of the outer peripheral surface 34 of the rotor body 31 of the rotor 3 , thereby absorbing, along with the first bushing 4 a and the second bushing 4 b , rattling due to decentering and others of the shaft for transmitting the external rotation force to the rotor 3 , and this causes the shaft to be rotatable smoothly.
- the first bushing 4 a is located axially outside the first sealing ring 8 a (See FIG. 2(A) and FIG. 4(A) ), but not limited in this respect: the first bushing 4 a may be located axially inside the first sealing ring 8 a .
- the second bushing 4 b is located axially outside the second sealing ring 8 b (See FIG. 2(A) , FIG. 3(A) , and FIG. 3(B) ); however, the second bushing 4 b may be located axially inside the second sealing ring 8 b .
- the circular cylindrical chamber 21 inside the case 2 holds the viscous fluid excellent in lubricating properties, and therefore the first bushing 4 a and the second bushing 4 b are lubricated by the viscous fluid held in the circular cylindrical chamber inside the case 2 to hold the rotor 3 rotatable more smoothly.
- each of the first and second sealing rings 8 a , 8 b use as each of the first and second sealing rings 8 a , 8 b , a member having the inner peripheral annular part 81 having a rectangular cross-section and including the inner peripheral surface 84 , the outer peripheral annular part 82 having a rectangular cross-section and including the outer peripheral surface 85 , and the coupling part 83 providing the connection between the inner peripheral annular part 81 and the outer peripheral annular part 82 ; however the scope of the present invention is not limited in this respect.
- each of the first and second sealing rings 8 a , 8 b may include an annular member that is rectangular in cross section and has the inner peripheral surface 84 and the outer peripheral surface 85 .
- each of the first and second sealing rings 8 a , 8 b is designed such that the width t6 of the corresponding inner peripheral surface 84 is smaller than the width t7 of the corresponding outer peripheral surface 85 , resulting in occurrence of slide between the corresponding inner peripheral surface 84 and its counterpart surface.
- the scope of the present invention is not limited in this respect.
- each of the first and second sealing rings 8 a , 8 b may be designed such that the width t7 of the corresponding outer peripheral surface 85 is smaller than the width t6 of the corresponding inner peripheral surface 84 , thereby enabling the corresponding outer peripheral surface 85 to slide relative to its counterpart surface.
- each of the first and second sealing rings 8 a , 8 b may be designed such that the width t6 of the corresponding inner peripheral surface 84 is about equal to the width t7 of the outer peripheral surface 85 , thereby causing the inner peripheral surface 84 and the outer peripheral surface 85 to be slidable relative to the respective counterpart surfaces.
- the circumferential grease grooves 86 are formed on the inner peripheral surfaces 84 of the first and second sealing rings 8 a , 8 b , and the grease is filled in these grease grooves 86 .
- the scope of the present invention is not limited in this respect.
- the circumferential grease groove(s) may be formed on at least one surface slidable to its counterpart surface, out of two surfaces that are the inner peripheral surface 84 and the outer peripheral surface 85 , and grease may be filled in the grease groove(s).
- the inner peripheral surface 84 and the outer peripheral surface 85 , of each of the first and second sealing rings 8 a , 8 b are flat in the direction of the center axis 20 of the circular cylindrical chamber 21 ; however, the scope of the present invention is not limited in this respect. Any surface can be available as either the inner peripheral surface 84 or the outer peripheral surface 85 , of each of the first and second sealing rings 8 a , 8 b , as far as it has a width in the direction of the center axis 20 of the circular cylindrical chamber 21 .
- FIG. 11(A) is a front view of each of modifications 8 ′ a , 8 ′ b of the first and second sealing rings 8 a , 8 b
- FIG. 11(B) is an I-I cross-section view of each modification 8 ′ a , 8 ′ b as illustrated in FIG. 11(A)
- FIG. 11(C) is an enlarged view of the part G of each modification 8 ′ a , 8 ′ b as illustrated in FIG. 11(B) .
- modifications 8 ′ a , 8 ′ b are, as with the first and second sealing rings 8 a , 8 b , annular members made of elastic material, such as nitrile butadiene rubber: the modification 8 ′ a of the first sealing ring 8 a has an inner diameter d1 smaller than an outer diameter d4 of the lower end part 33 a of the rotor body 31 of the rotor 3 and an outer diameter d2 larger than an inner diameter d3 of the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 (an outer diameter of the step 221 ); and the modification 8 ′ b of the second sealing ring 8 b has an inner diameter d1 smaller than an outer diameter d5 of the upper end part 33 b of the rotor body 31 of the rotor 3 and an outer diameter d2 larger than an inner diameter d6 of the through-hole 60 in the lid (an outer diameter of the step).
- these modifications 8 ′ a , 8 ′ b each have an inner peripheral surface 84 ′ with the width t6 in the direction of the center axis 80 and an outer peripheral surface 85 ′ with the width t7 in the direction of the center axis 80 .
- the width t6 of the inner peripheral surface 84 ′ and the width t7 of the outer peripheral surface 85 ′ are equal in length, but both may be different in length.
- the inner peripheral surface 84 ′ is a curved surface along arc having a radius r1 larger than half of a radial width t10 of the modification 8 ′ a , 8 ′ b in the direction of the center axis 80 coincident with the center axis 20 of the circular cylindrical chamber 21 inside the case 2 : for the modification 8 ′ a of the first sealing ring 8 a , the inner peripheral surface 84 ′ is pressed against the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31 of the rotor 3 , whereas for the modification 8 ′ b of the second sealing ring 8 b , against the outer peripheral surface 34 of the upper end part 33 b of the rotor body 31 of the rotor 3 .
- the outer peripheral surface 85 ′ is a curved surface along an arc having a radius r2 larger than half of the radial width t10 of the modification 8 ′ a , 8 ′ b in the direction of the center axis 80 ; for the modification 8 ′ a of the first sealing ring 8 a , the outer peripheral surface 85 ′ is pressed against the inner peripheral surface 220 of the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 , whereas for the modification 8 ′ b of the second sealing ring 8 b , against the inner peripheral surface 64 of the through-hole 60 in the lid 6 .
- valve seal 5 attached to each vane 32 serves as a check valve for opening and closing the flow passage 36 formed through the corresponding vane 32 , but the scope of the present invention is not limited in this respect.
- check valves may be used which close the flow passages 36 formed in the respective vanes 32 on rotating the rotor 3 in the first rotating direction R1 relative to the circular cylindrical chamber 21 and which open the flow passages 36 formed in the respective vanes 32 on rotating the rotor 3 in the second rotating direction R2 relative to the circular cylindrical chamber 21 .
- the flow passages 36 are each formed in the corresponding vane 32 along the rotation direction of the rotor 3 so as to pass through the both side faces 37 a , 37 b of the corresponding vane 32 , but the scope of the present invention is not limited in this respect.
- the partitioning parts 25 instead of the vanes 32 or not only in the vanes 32 but also in the partitioning parts 25 , such flow passages may be formed along the rotation direction of the rotor 3 .
- check valves may be installed which close the respective flow passages formed in the partitioning parts 25 upon rotating the rotor 3 in the first rotating direction R1 relative to the circular cylindrical chamber 21 and open the respective flow passages formed in the partitioning parts 25 upon rotating the rotor in the second rotating direction R2 relative to the circular cylindrical chamber 21 .
- the partitioning parts 25 may each have a seal member attached thereto to serve similarly to the valve seal 5 , that is, a seal member including a bottom part having a width longer than a circumferential directional width of an inner peripheral edge of the corresponding partitioning part 25 , a first branch formed integrally with one edge of the bottom part and having a width longer than a radial directional width of the flow passage formed through the corresponding partitioning part 25 , and a second branch formed integrally with another edge of the bottom part and having a width shorter than a radial directional width of the flow passage formed in the corresponding partitioning part 25 .
- a seal member including a bottom part having a width longer than a circumferential directional width of an inner peripheral edge of the corresponding partitioning part 25 , a first branch formed integrally with one edge of the bottom part and having a width longer than a radial directional width of the flow passage formed through the corresponding partitioning part 25 , and a second branch formed integrally with another edge of the bottom part
- Rotating rotor 3 in the first rotating direction R1 relative to the circular cylindrical chamber 21 causes each of the seal members to bring the first branch into contact with one side of the corresponding partitioning part 25 , thereby closing the flow passage formed in each of the partitioning parts 25
- rotating the rotor 3 in the second rotating direction R2 relative to the circular cylindrical chamber 21 causes each of the seal member to move the first branch away from one side of the corresponding partitioning part 25 and to bring the second branch into contact with another side of the corresponding partitioning part 25 , thereby opening the flow passage formed in each of the partitioning parts 25 .
- valve seal 5 may have any shape as long as it can close the gap between the front face 35 of the vane 32 and the inner peripheral surface 24 of the circular cylindrical chamber 21 .
- the valve seal 5 may be omitted.
- the internal threaded section 27 is formed on the opening side 28 of the inner peripheral surface 24 of the circular cylindrical chamber 21
- the external threaded section 62 is formed on the outer peripheral surface 61 of the lid 6 so as to be screwed into this internal threaded section 27
- the lid 6 is thereby fixed to the case 2 .
- the scope of the present invention is not limited in this respect.
- the lid 6 may be fixed to the case 2 , for example, by bolts or by rivets.
- the lid 6 and the case 2 may be joined by joining way, such as gluing or welding.
- the external rotation force is applied to the rotor 3 , thus rotating the rotor 3 relative to the circular cylindrical chamber 21 inside the case 2 .
- the scope of the present invention is not limited in this respect. Applying the external rotation force to the case 2 may rotate the rotor 3 relative to the circular cylindrical chamber 21 inside the case 2 .
- the above embodiments have been described taking the example of the so-called uni-directional rotary damper 1 in which rotating the rotor 3 in the first rotating direction R1 relative to the circular cylindrical chamber 21 causes a higher damping torque than if rotating the rotor 3 in the second rotating direction R2 relative to the circular cylindrical chamber 21 .
- the scope of the present invention is not limited in this respect.
- the present invention may be applied to any so-called bi-directional rotary damper that can work in both the first rotating direction R1 and the second rotating direction R2 so as to cause a damping torque depending on the resistance to motion of the viscous fluid passing through the flow passage formed in each of the vanes 32 or in each of the partitioning parts (the degree to which the viscous fluid is hard to be moved through the flow passage).
- valve seal 5 may not necessarily need to serve as a check valve.
- the valve seal 5 may be anything as long as it can fill the gap between the front face 35 of the corresponding vane 32 and the inner peripheral surface 24 of the circular cylindrical chamber 21 .
- the valve seal 5 may be omitted.
- the above embodiment has been described taking the example of the rotary damper 1 that generates the damping torque in reaction to the external rotation force by limiting movement of the viscous fluid.
- the present invention can include, but is not limited to, the above embodiment.
- the present invention can be widely applied to any damper that generates a damping force in reaction to an external force by limiting a movement of viscous fluid.
- FIG. 12(A) is a side view of a linear type damper 9 according to another embodiment of the present invention
- FIG. 12(B) is a J-J cross-section view of the linear type damper as illustrated in FIG. 12(A) .
- the linear type damper 9 is available for any device in which a linear motion of a moving object is to be damped, such as seats with height adjustment function and movable shelves.
- the linear type damper 9 has the following: a case 920 and a lid 960 that form the fluid holding chamber holding the viscous fluid (not illustrated in the figures), such as oil or silicone; and a shaft 930 housed in the fluid holding chamber so as to be linearly movable relative to the fluid holding chamber in a direction of a center axis 902 .
- a circular cylindrical chamber 921 with one end open i.e. a space having a circular cylindrical shape with a bottom
- an insertion hole 923 for insertion of the shaft 930 is formed in a bottom part 922 of this circular cylindrical chamber 921 .
- a first sealing ring 980 a and a first bushing 990 a are attached to this insertion hole 923 , and then the insertion of one end part 933 a of a below-mentioned shaft body 931 into the insertion hole 923 having these first sealing ring 980 a and first bushing 990 a attached thereto places the shaft 930 in the circular cylindrical chamber 921 so as to align a center axis 903 of the shaft 930 with the center axis 902 of the circular cylindrical chamber 921 .
- a mounting section 927 for attachment of the first sealing ring 980 a and the first bushing 990 a is formed in an inner peripheral surface 929 of the insertion hole 923 to be in a stepped annular groove shape.
- a through-hole 926 for air vent is formed through a bottom part 925 inside the insertion hole 923 .
- the lid 960 is fixed onto the opening side 928 of an inner peripheral surface 924 of the circular cylindrical chamber 921 by jointing way, such as threaded joint, gluing, welding, fastening with a screw, and fastening with a machine screw.
- the shaft 930 includes the shaft body 931 in a substantial cylindrical shape and a flange 932 formed near or at the middle of length of the shaft body 931 .
- the flange 932 projects, near or at the middle of length of the shaft body 931 , radially outward from an outer peripheral surface 934 of the shaft body 931 so as to place its front face 935 close to the inner peripheral surface 924 of the circular cylindrical chamber 921 inside the case 920 , thereby partitioning the inside of the circular cylindrical chamber 921 .
- the flange 932 forms volume changing means to compress one area and expand another area within the circular cylindrical chamber 921 partitioned by the flange 932 according to linear motion in a direction along the center axis 903 of the shaft 930 .
- flow passages 936 are formed along the direction of the center axis 903 of the shaft 930 so as to pass through both side face 937 a , 937 b of the flange 932 .
- Check valves 970 are installed in the respective flow passages 936 so as to close the respective flow passages 936 in case of moving the shaft 930 , along the center axis 902 of the circular cylindrical chamber 921 , in a first moving direction L1, and so as to open the respective flow passages 936 in another case of moving the shaft 930 in a second moving direction L2, namely, a direction opposite to the first moving direction L1.
- a gap g′ is formed between the outer peripheral surface 935 of the flange 932 and the inner peripheral surface 924 of the circular cylindrical chamber 921 inside the case 920 so as to work as a flow passage for the viscous fluid filled within the circular cylindrical chamber 921 .
- the shaft body 931 serves as a resistance generating member capable of moving in the direction of the center axis 902 of the circular cylindrical chamber 921 relative to the circular cylindrical chamber 921 in reaction to the external force in the direction of the center axis 903 of the shaft 930 .
- one end part 933 a is to be inserted into the insertion hole 923 formed in the bottom part 922 of the circular cylindrical chamber 921 inside the case 920 so as to be movable in the direction of the center axis 902 of the circular cylindrical chamber 921
- another end part 933 b is to be inserted into a through-hole 961 in the lid 960 so as to be movable in the direction of the center axis 902 of the circular cylindrical chamber 921 .
- the through-hole 961 for insertion of the shaft 930 which serves as the opening section of the fluid holding chamber, is formed at a place opposite to the insertion hole 923 formed in the bottom part 922 of the circular cylindrical chamber 921 inside the case 920 .
- a second sealing ring 980 b and a second bushing 990 b are attached to this through-hole 961 , another end part 933 b of the shaft body 931 of the shaft 930 is inserted into the through-hole 961 to which these second sealing ring 980 b and second bushing 990 b are attached.
- a mounting section 962 for attachment of the second sealing ring 980 b and the second bushing 990 b is formed in an inner peripheral surface 964 of the through-hole 961 to be in a stepped annular groove shape.
- the first bushing 990 a and the second bushing 990 b are each a cylindrical member made of material excellent in sliding properties: the first bushing 990 a has an inner peripheral surface slidable to the outer peripheral surface 934 of the shaft body 931 of the shaft 930 and an outer peripheral surface to abut the inner peripheral surface 929 of the insertion hole 923 of the circular cylindrical chamber 921 inside the case 920 ; and the second bushing 990 b has an inner peripheral surface slidable to the outer peripheral surface 934 of the shaft body 931 of the shaft 930 and an outer peripheral surface to abut the inner peripheral surface 964 of the through-hole 961 in the lid 960 .
- the first bushing 990 a and the second bushing 990 b may each be made of metal, such as brass alloy, or synthetic resin, such as PTFE, polyacetal resin, polyethylene resin, polyamide resin, and polyphenylene sulfide resin.
- the first bushing 990 a and the second bushing 990 b may each be made of such multi-layer sliding material that on an inner peripheral surface of a backing material in a cylindrical shape are formed a plurality of sliding layers each including a woven or a non-woven fabric impregnated with synthetic resin, such as phenolic resin.
- the first and second sealing rings 980 a , 980 b are each an annular member made of elastic material, such as nitrile butadiene rubber.
- the first sealing ring 980 a includes an inner peripheral surface having a width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being slidably pressed against the outer peripheral surface 934 of the shaft body 931 and an outer peripheral surface having a width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being pressed against a groove bottom inside the mounting section 927 formed in the inner peripheral surface 929 of the insertion hole 923 of the case 920 .
- the second sealing ring 980 b includes an inner peripheral surface having a width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being slidably pressed against the outer peripheral surface 934 of the shaft body 931 and an outer peripheral surface having a width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being pressed against a groove bottom inside the mounting section 962 formed in the inner peripheral surface 964 of the through-hole 961 in the lid 960 .
- the first and second sealing rings 980 a , 980 b may respectively be the first and second sealing rings 8 a , 8 b as illustrated in FIG. 10 or be the modifications 8 ′ a , 8 ′ b of the first and second sealing rings 8 a , 8 b as illustrated in FIG. 11 , for example.
- the linear type damper 9 with the structure as described above also achieves an advantage similar to that of the rotary damper 1 as illustrated in FIG. 1 .
- the shaft 930 is slidably held by both the first bushing 990 a and the second bushing 990 b respectively attached to the insertion hole 923 of the circular cylindrical chamber 921 inside the case 920 and the through-hole 961 in the lid 960 , and therefore the misalignment of the shaft 930 is suppressed even without enhancement of the stiffness of the first sealing ring 980 a and the second sealing ring 980 b which along with the first bushing 990 a and the second bushing 990 b hold the shaft 930 slidable.
- first sealing ring 980 a and the second sealing ring 980 b to be each designed to have such low stiffness that the both rings 980 a , 980 b can be elastically deformed depending on movement of the shaft 930 , thereby resulting in no gap between the shaft 930 and both the first sealing ring 980 a and the second sealing ring 980 b and in resultant decrease of the likelihood of external leakage of the viscous fluid held within the circular cylindrical chamber 921 inside the case 920 .
- the first sealing ring 980 a is located between the insertion hole 923 of the circular cylindrical chamber 921 inside the case 920 and one end part 933 a of the shaft body 931 of the shaft 930
- the second sealing ring 980 b is located between the through-hole 961 in the lid 960 and another end part 933 b of the shaft body 931
- the first sealing ring 980 a includes an inner peripheral surface having the width that is flat in the direction of the center axis 902 of the circular cylindrical chamber 921 and being slidably pressed against the outer peripheral surface 934 of the shaft body 931 and an outer peripheral surface having the width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being pressed against the groove bottom inside the mounting section 927 formed in the inner peripheral surface 929 of the insertion hole 923 of the case 920
- the second sealing ring 980 b includes an inner peripheral surface having the width in the direction of the center axis 902 of the
Abstract
Description
- The present invention relates to a damper that limits the movement of viscous fluid to apply a damping force in reaction to an external force.
- A known damper gives a damping force in reaction to an external force by limiting a movement of a viscous fluid. This type of damper has a fluid holding chamber having opening sections and holding the viscous fluid, a resistance generating member partitioning an inside of the fluid holding chamber and inserted in the opening sections of the fluid holding chamber so as to move or rotate relative to the fluid holding chamber by receiving the external force, volume changing means partitioning the inside of the fluid holding chamber and capable of compressing one area and expanding another area within the partitioned fluid holding chamber according to the movement or the rotation of the resistance generating member relative to the fluid holding chamber, and a flow passage connecting between the areas within the fluid holding chamber partitioned by the volume changing means.
- For example, the
Patent Literature 1 discloses a rotary damper for generating a damping torque in reaction to an applied rotation force by limiting the movement of a viscous fluid. This rotary damper has a housing having an inner chamber with one end opened, a rotor housed within the inner chamber of the housing, the viscous fluid (fluid substance) filled within the inner chamber of the housing, and a plug attached to an opening side end of the housing so as to seal in the viscous fluid filled within the inner chamber of the housing. The housing and the plug together form the fluid holding chamber. - The rotor has a rotor body in a substantial circular cylinder shape and movable vanes projecting radially outward from an outer peripheral surface of the rotor body toward an inner peripheral surface of the inner chamber of the housing. The rotor body corresponds to the resistance generating member.
- Fixed vanes are formed on the inner peripheral surface of the inner chamber of the housing, each projecting radially inward toward an outer peripheral surface of the rotor body to partition the inner chamber of the housing. The fixed vanes, with the movable vanes of the rotor, form the volume changing means together.
- Flow passages (i.e. orifices) are formed through the respective fixed vanes of the housing so as to connect between the respective areas into which the inner chamber of the housing is partitioned by the respective fixed vanes.
- A bottom of the inner chamber of the housing and the plug each include a through-hole for rotatable insertion of a corresponding end part of the rotor body. These through-holes correspond the opening sections of the fluid holding chamber. One end part of the rotor body is inserted into the through-hole formed in the bottom of the inner chamber of the housing, another end part of the rotor body is inserted into the through-hole formed in the plug, and the rotor is thereby housed within the inner chamber of the housing so as to be rotatable relative to this inner chamber.
- In the structure as described above, as for the rotary damper, when the rotation force is applied to the rotor to rotate the rotor relative to the inner chamber of the housing, each of the movable vanes compresses the area located upstream in a rotor rotation direction from the corresponding fixed vane of the inner chamber and a pressure on the viscous fluid in this area is increased. This causes the viscous fluid in this area to pass through the flow passage formed in the corresponding fixed vane and to moves to the area located downstream in the rotor rotation direction from the corresponding fixed vane of the inner chamber. At this time, the damping torque generates depending on a resistance to motion of the viscous fluid (the degree to which the viscous fluid is hard to be moved through the flow passage).
- Patent Literature 1: Japanese Unexamined Patent Application Laid-Open No. 2014-005883
- Generally, in the damper for applying the damping force in reaction to the external force by limiting the movement of the viscous fluid, an O-ring made of an elastic body such as rubber is arranged between each opening section of the fluid holding chamber and the resistance generating member inserted in this opening section in order to prevent leakage of the viscous fluid held in the fluid holding chamber through a gap therebetween. Therefore, the following may occurs.
- Specifically, it may occur that the external force applied to the resistance generating member deforms the O-ring elastically to deviate a center axis of the resistance generating member from a center axis of the fluid holding chamber, thus causing misalignment. In order to reduce such misalignment, stiffness of the O-ring is to be enhanced. Enhancement of the stiffness of the O-ring may, however, cause the O-ring to resist elastic deformation depending on the movement or the rotation of the resistance generating member and then generate a gap between the resistance generating member and the O-ring, thus resulting in leakage of the viscous fluid held in the fluid holding chamber through this gap.
- Moreover, the O-ring, since having a circular cross-section, varies in respective contact areas between it and the resistance generating member and between it and the opening section of the fluid holding chamber when it is elastically deformed in its radial direction. This may lead to instability of a seal between the resistance generating member and the opening section of the fluid holding chamber, thus further increasing the likelihood of external leakage of the viscous fluid held in the fluid holding chamber through the gap therebetween.
- The present invention has been made in view of the above situation, and an object of the invention is to provide a damper capable of ensuring against the leakage of the viscous fluid held in the fluid holding chamber.
- In response to the above issue, for a damper of the present invention, a bushing is attached to an opening section of a fluid holding chamber so that a resistance generating member is slidably held by this bushing, and an elastic member in an annular shape is located between the resistance generating member held by this bushing and the opening section of the fluid holding chamber and has the following: an outer peripheral surface having a width in a direction of a center axis of the fluid holding chamber and being pressed against the fluid holding chamber; and an inner peripheral surface having a width in the direction of the center axis of the fluid holding chamber and being pressed against the resistance generating member.
- For example, the present invention provides a damper for generating a damping force in reaction to an external force by limiting a movement of a viscous fluid, and the damper includes the following:
- a fluid holding chamber having the opening section and holding the viscous fluid within;
- a resistance generating member inserted in the opening section of the fluid holding chamber and movable relative to the fluid holding chamber in reaction to the external force;
- volume changing means partitioning an inside of the fluid holding chamber and configured to compress one of areas within the fluid holding chamber partitioned and expand another of the areas, with a movement of the resistance generating member relative to the fluid holding chamber;
- a flow passage connecting between the areas within the fluid holding chamber partitioned by the volume changing means;
- a bushing attached to the opening section of the fluid holding chamber and holding slidable the resistance generating member inserted in the opening section of the fluid holding chamber; and
- an elastic member in an annular shape located between the resistance generating member held by the bushing and the opening section of the fluid holding chamber.
- The elastic member includes the following:
- an inner peripheral surface having the width in the direction of the center axis of the fluid holding chamber and being pressed against the resistance generating member; and
- an outer peripheral surface having the width in the direction of the center axis of the fluid holding chamber and being pressed against the fluid holding chamber.
- According to the present invention, the bushing attached to the opening section of the fluid holding chamber holds the resistance generating member slidable, therefore resulting in reduction of a misalignment of the resistance generating member even without enhancement of stiffness of the elastic member. This allows the elastic member to be designed to have low stiffness so that it can deform elastically depending on movement or rotation of the resistance generating member, thereby resulting in no gap between the resistance generating member and the elastic member to decrease the likelihood of external leakage of the viscous fluid held in the fluid holding chamber.
- Furthermore, according to the present invention, the elastic member in an annular shape, which includes the inner peripheral surface and the outer peripheral surface each having the width in the direction of the center axis of the fluid holding chamber, is located between the resistance generating member held by bushing and the opening section of the fluid holding chamber. This enables resultant reduction of changes in respective contact areas between the elastic member and the resistance generating member and between the elastic member and the fluid holding chamber, even if misalignment of the resistance generating member occurs to cause elastic deformation of the elastic member in the radial direction. Consequently, seal tightness between the opening section of the fluid holding chamber and the resistance generating member becomes stable, thus resulting in further decrease of the likelihood of external leakage of the viscous fluid held in the fluid holding chamber.
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FIGS. 1(A) to 1(C) are respectively a front view, a side view, and a back view, of arotary damper 1 according to one embodiment of the present invention. -
FIG. 2(A) is an A-A cross-section view of therotary damper 1 as illustrated inFIG. 1(A) , andFIG. 2(B) is a B-B cross-section view of therotary damper 1 as illustrated inFIG. 1(B) . -
FIG. 3(A) andFIG. 3(B) are respectively an enlarged view of the part A and an enlarged view of the part B, of therotary damper 1 as illustratedFIG. 2(A) . -
FIG. 4(A) is an enlarged view of the part C of therotary damper 1 as illustratedFIG. 2(A) , andFIG. 4(B) is an enlarged view of the part D of therotary damper 1 as illustrated inFIG. 2(B) . -
FIG. 5(A) is a front view of acase 2,FIG. 5(B) is a C-C cross-section view of thecase 2 as illustrated inFIG. 5(A) , andFIG. 5(C) is a back view of thecase 2. -
FIG. 6(A) andFIG. 6(B) are respectively a front view and a side view, of arotor 3, andFIG. 6(C) is a D-D cross-section view of therotor 3 as illustrated inFIG. 6(A) . -
FIG. 7(A) andFIG. 7(B) are respectively a side view and a front view, of each of the first andsecond bushings FIG. 7(C) is an E-E cross-section view of each of the first andsecond bushings FIG. 7(B) . -
FIG. 8(A) andFIG. 8(B) are respectively a front view and a side view, of avalve seal 5, andFIG. 8(C) is an F-F cross-section view of thevalve seal 5 as illustrated inFIG. 8(A) . -
FIGS. 9(A) to 9(C) are a front view, a side view, and a back view, of alid 6, andFIG. 9(D) is a G-G cross-section view of thelid 6 as illustrated inFIG. 9(A) . -
FIG. 10(A) is a front view of each of the first andsecond sealing rings FIG. 10(B) is an H-H cross-section view of each of the first andsecond sealing rings FIG. 10(A) ,FIG. 10(C) is an enlarged view of the part E of each of the first andsecond sealing rings FIG. 10(A) , andFIG. 10(D) is an enlarged view of the part F of each of the first andsecond sealing rings FIG. 10(B) . -
FIG. 11(A) is a front view of each of modifications 8′a, 8′b of the first andsecond sealing rings FIG. 11(B) is an I-I cross-section view of each modification 8′a, 8′b as illustrated inFIG. 11(A) , andFIG. 11(C) is an enlarged view of the part G of each modification 8′a, 8′b as illustrated inFIG. 11(B) . -
FIG. 12(A) is a side view of alinear type damper 9 according to another embodiment of the present invention, andFIG. 12(B) is a J-J cross-section view of the linear type damper as illustrated inFIG. 12(A) . - In the following, one embodiment of the present invention will be described referring to the drawings.
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FIGS. 1(A) to 1(C) are respectively a front view, a side view, and a back view, of arotary damper 1 according to the embodiment of the present invention.FIG. 2(A) is an A-A cross-section view of therotary damper 1 as illustrated inFIG. 1(A) , andFIG. 2(B) is a B-B cross-section view of therotary damper 1 as illustrated inFIG. 1(B) .FIG. 3(A) andFIG. 3(B) are respectively an enlarged view of the part A and an enlarged view of the part B, of therotary damper 1 as illustratedFIG. 2(A) .FIG. 4 (A) is an enlarged view of the part C of therotary damper 1 as illustratedFIG. 2(A) , andFIG. 4(B) is an enlarged view of the part D of therotary damper 1 as illustrated inFIG. 2(B) . - The
rotary damper 1 according to the present embodiment can be used for any device in which a rotational motion of a bi-directionally rotatable rotator is to be damped, such as seats with reclining function for use in any apparatuses, for example, automobiles, railroad vehicles, aircrafts, and vessels. As illustrated in the figures, therotary damper 1 according to the present embodiment includes the following: acase 2 and alid 6 that form a fluid holding chamber holding a viscous fluid (not illustrated in the figures), such as oil or silicone; and arotor 3 housed in the fluid holding chamber so as to be rotatable relative to the fluid holding chamber. -
FIG. 5(A) is a front view of thecase 2,FIG. 5(B) is a C-C cross-section view of thecase 2 as illustrated inFIG. 5(A) , andFIG. 5(C) is a back view of thecase 2. - As illustrated in the figures, a circular
cylindrical chamber 21 with one end opened (i.e. a space having a circular cylindrical shape with a bottom) is formed inside of thecase 2, and a through-hole 23 for insertion of therotor 3 is formed in abottom part 22 of this circularcylindrical chamber 21 so as to serve as an opening section of the fluid holding chamber. Below-mentionedfirst sealing ring 8 a andfirst bushing 4 a (SeeFIG. 4(A) ) are fitted in this through-hole 23; alower end part 33 a of a below-mentioned rotor body 31 (SeeFIG. 6 ) is inserted into the through-hole 23 in which thesefirst sealing ring 8 a andfirst bushing 4 a are already fitted, and therotor 3 is thereby housed within the circularcylindrical chamber 21 so as to align arotation axis 30 of therotor 3 with acenter axis 20 of the circular cylindrical chamber 21 (SeeFIG. 2(A) andFIG. 4(A) ). Astep 221 and astep 222 are formed on an innerperipheral surface 220 of the through-hole 23 of the circularcylindrical chamber 21 so as to restrict respectively thefirst sealing ring 8 a and thefirst bushing 4 a from moving axially outward (i.e. toward the outside of thecase 2 in an axial direction of the rotary damper 1). - A pair of
partitioning parts 25 along thecenter axis 20 of the circularcylindrical chamber 21 is formed on an innerperipheral surface 24 of the circularcylindrical chamber 21 so as to be axisymmetrically with respect to thiscenter axis 20, and thepartitioning parts 25 project radially inward so as to place respective front faces 26 close to an outerperipheral surface 34 of the below-mentioned rotor body 31 (SeeFIG. 6 ) of therotor 3, thereby partitioning an inside of the circularcylindrical chamber 21. Moreover, an internal threadedsection 27 is formed on anopening side 28 of the innerperipheral surface 24 of the circularcylindrical chamber 21 so as to be screwed onto a below-mentioned external threaded section 62 (SeeFIG. 9 ) of thelid 6. -
FIG. 6(A) andFIG. 6(B) are respectively a front view and a side view, of therotor 3, andFIG. 6(C) is a D-D cross-section view of therotor 3 as illustrated inFIG. 6(A) . - As illustrated in the figures, the
rotor 3 includes therotor body 31 in a cylindrical shape and a pair of vanes (rotor blades) 32 formed axisymmetrically with respect to therotation axis 30 of therotor body 31. - Each of the
vanes 32 is formed along therotation axis 30 of therotor 31 and projects radially outward from the outerperipheral surface 34 of therotor body 3 so as to place a correspondingfront face 35 close to the innerperipheral surface 24 of the circularcylindrical chamber 21 inside thecase 2, thereby partitioning the inside of the circularcylindrical chamber 21. Thevanes 32, along with thepartitioning parts 25 of the circularcylindrical chamber 21 within thecase 2, form volume changing means to compress and expand respectively one area and another area into which the fluid holding chamber is partitioned by thevanes 32. - A
flow passage 36 is formed in each of thevanes 32 along a rotation direction of therotor 3 so as to pass through both side faces 37 a, 37 b of the correspondingvane 32. Moreover, avalve seal 5 is attached to each of the vanes 32 (SeeFIG. 2(B) andFIG. 4(B) ). - The
rotor body 31 of therotor 3 works as a resistance generating member capable of rotating relative to the fluid holding chamber in reaction to an external force. For therotor body 31, thelower end part 33 a is to be rotatably inserted into the through-hole 23 formed in the bottom part of the circularcylindrical chamber 21 within the case 2 (SeeFIG. 2(A) andFIG. 4(A) ) and anupper end part 33 b is to be rotatably inserted into a below-mentioned through-hole (SeeFIG. 9 ) in the lid 6 (SeeFIG. 2(A) ,FIG. 3(A) , andFIG. 3(B) ). - The
rotor body 31 includes ainsertion hole 38 formed with therotation axis 30 as center so that a shaft with machined double flats (not illustrated in the figures) for transmitting the external rotation force to therotor 3 is to be inserted into thehole 38. Thelower end part 33 a of therotor body 31 is to be rotatably inserted into below-mentionedfirst sealing ring 8 a and thefirst bushing 4 a both attached to the through-hole 23 of the circularcylindrical chamber 21 inside the case 2 (SeeFIG. 4(A) ). Astep 340 a is formed on the outerperipheral surface 34 of thelower end part 33 a of therotor body 31 so as to restrict thefirst sealing ring 8 a and thefirst bushing 4 a from moving axially inward (i.e. toward the inside of thecase 2 in the axial direction of the rotary damper 1). Theupper end part 33 b of therotor body 31, whereas, is to be rotatably inserted into asecond sealing ring 8 b and asecond bushing 4 b both attached to the below-mentioned through-hole 60 in the lid 6 (SeeFIG. 3(A) andFIG. 3(B) ). Furthermore, astep 340 b is formed on the outerperipheral surface 34 of theupper end part 33 b of therotor body 31 so as to restrict thesecond sealing ring 8 b and thesecond bushing 4 b from moving axially inward. -
FIG. 7(A) andFIG. 7(B) are respectively a side view and a front view, of each of the first andsecond bushings FIG. 7(C) is an E-E cross-section view of each of the first andsecond bushings FIG. 7(B) . - As illustrated in the figures, the
first bushing 4 a and thesecond bushing 4 b are each a cylindrical member made of material excellent in sliding properties: thefirst bushing 4 a has an innerperipheral surface 40 a slidable relative to the outerperipheral surface 34 of thelower end part 33 a of therotor body 31 of therotor 3 and an outerperipheral surface 41 a to abut the innerperipheral surface 220 of the through-hole 23 of the circularcylindrical chamber 21 inside thecase 2, and thesecond bushing 4 b has an innerperipheral surface 40 b slidable relative to the outerperipheral surface 34 of theupper end part 33 b of therotor body 31 of therotor 3 and an outerperipheral surface 41 b to abut an innerperipheral surface 64 of the through-hole 60 in the lid 6 (SeeFIG. 9(D) ). - The
first bushing 4 a and thesecond bushing 4 b are each made of metal, such as brass alloy, or synthetic resin, such as PTFE (polytetrafluoroethylene), polyacetal resin, polyethylene resin, polyamide resin, and polyphenylene sulfide resin. Alternatively, thefirst bushing 4 a and thesecond bushing 4 b may each be made of such multi-layer sliding material in which a plurality of sliding layers are formed on an inner peripheral surface of a backing material, such as cylindrical steel plate or resin composite in a cylindrical shape. Used may be a multi-layer sliding material such that a sintered metallic layer is formed on an inner peripheral surface of a backing material made of a cylindrical steel plate and a sliding resin layer containing PTFE is further formed overlying there, for example. -
FIG. 8(A) andFIG. 8(B) are respectively a front view and a side view, of thevalve seal 5, andFIG. 8(C) is an F-F cross-section view of thevalve seal 5 as illustrated inFIG. 8(A) . - As illustrated in the figures, each of the valve seals 5, which has a U-shape attachable to the corresponding
vane 32 of therotor 3, includes abottom part 50 having a width t2 longer than a rotational directional width t1 (SeeFIG. 6(A) ) of the correspondingvane 32, afirst branch 53 formed integrally with oneedge 51 of thebottom part 50 and having a width t4 longer than a radial directional width t3 (SeeFIG. 6(B) ) of theflow passage 36 formed through the correspondingvane 32, and asecond branch 54 formed integrally with anotheredge 52 of thebottom part 50 and having a width t5 shorter than the radial directional width t3 of theflow passage 36 formed through the correspondingvane 32. - The valve seals 5 attached to the
vanes 32 is each located so as to interpose thebottom part 50 between thefront face 35 of the correspondingvane 32 and the innerperipheral surface 24 of the circularcylindrical chamber 21 inside thecase 2, thereby sealing a gap therebetween (SeeFIG. 4(B) ). As illustrated inFIG. 2(B) , rotating therotor 3 in a first rotating direction R1 relative to the circularcylindrical chamber 21 inside thecase 2, causes each of thevalve seal 5 to bring thefirst branch 53 into contact with one side face 37 a of the correspondingvane 32, thereby closing theflow passage 36 formed through each of thevanes 32. And conversely, rotating therotor 3 in a second rotating direction R2, namely in the direction opposite to the first rotating direction R1, relative to the circularcylindrical chamber 21 inside thecase 2, causes each of the valve seals 5 to move thefirst branch 53 away from one side face 37 a of the correspondingvane 32 and to bring thesecond branch 54 into contact with another side face 37 b of the correspondingvane 32, thereby opening theflow passage 36 formed through each of the vanes 32 (SeeFIG. 4(B) ). - Since each of the valve seals 5 is arranged between the
case 2 and therotor 3 which are rotatable relative to each other, material excellent in sliding properties, for example, synthetic resin, such as polyamide resin, may be preferably used for each the valve seals 5. -
FIGS. 9(A) to 9(C) are a front view, a side view, and a back view, of thelid 6, andFIG. 9(D) is a G-G cross-section view of thelid 6 as illustrated inFIG. 9(A) . - As illustrated in the figures, on the
lid 6, the through-hole 60 for insertion of therotor 3 is formed at a place opposite to the through-hole 23 formed in thebottom part 22 of the circularcylindrical chamber 21 inside thecase 2 so as to serve as an opening section of the fluid holding chamber. Thesecond sealing ring 8 b and thesecond bushing 4 b (SeeFIG. 3(A) ) each being described below, are attached to this through-hole 60, and theupper end part 33 b of therotor body 31 of therotor 3 is to be inserted into the through-hole 60 in which thesesecond sealing ring 8 b andsecond bushing 4 b are already fitted. Astep 65 and a step are formed on the innerperipheral surface 64 of the through-hole 60 so as to prevent thesecond sealing ring 8 b and thesecond bushing 4 b from moving axially outward, respectively. - On an outer
peripheral surface 61 of thelid 6, the external threadedsection 62 is formed so as to be screwed into the internal threadedsection 27 formed on theopening side 28 of the innerperipheral surface 24 of the circularcylindrical chamber 21, and furthermore acircumferential groove 67 for installation of an O-ring 7 is also formed on thelower face 63 side in relation to the external threadedsection 62. The O-ring 7 is installed in thegroove 67 and is interposed between the outerperipheral surface 61 of thelid 6 and the innerperipheral surface 24 of the circularcylindrical chamber 21, thereby preventing the viscous fluid from leaking outside through a threaded engagement section between the external threadedsection 62 of thelid 6 and the internal threadedsection 27 of the circular cylindrical chamber 21 (SeeFIG. 3(A) andFIG. 3(B) ). -
FIG. 10(A) is a front view of each of the first and second sealing rings 8 a, 8 b,FIG. 10(B) is an H-H cross-section view of each of the first and second sealing rings 8 a, 8 b as illustrated inFIG. 10(A) ,FIG. 10(C) is an enlarged view of the part E of each of the first and second sealing rings 8 a, 8 b as illustrated inFIG. 10(A) , andFIG. 10(D) is an enlarged view of the part F of the first and second sealing rings 8 a, 8 b as illustrated inFIG. 10(B) . - As illustrated in the figures, the
first sealing ring 8 a and thesecond sealing ring 8 b are each an annular member made of elastic material, such as nitrile butadiene rubber (NBR): thefirst sealing ring 8 a has an inner diameter d1 smaller than an outer diameter d4 of thelower end part 33 a of therotor body 31 of therotor 3 and an outer diameter d2 larger than an inner diameter (an outer diameter of the step 221) d3 of the through-hole 23 of the circularcylindrical chamber 21 inside thecase 2; and thesecond sealing ring 8 b has an inner diameter d1 smaller than an outer diameter d5 of theupper end part 33 b of therotor body 31 of therotor 3 and an outer diameter d2 larger than an inner diameter (an outer diameter of the step 65) d6 of the through-hole 60 in thelid 6. Moreover, thefirst sealing ring 8 a and thesecond sealing ring 8 b each include an inner peripheralannular part 81 rectangular in cross-section, an outer peripheralannular part 82 rectangular in cross-section, and acoupling part 83. - The inner peripheral
annular part 81 of eachring peripheral surface 84 having a width t6 that is flat in a direction of acenter axis 80 coincident with thecenter axis 20 of the circular cylindrical chamber inside thecase 2. Thefirst sealing ring 8 a and thesecond sealing ring 8 b each enable resultant reduction of any change in contact area between the corresponding innerperipheral surface 84 and its counterpart surface upon being elastically deformed in the radial direction because the corresponding innerperipheral surface 84 has the width t6 that is flat in the direction of thecenter axis 80. It is noted that the innerperipheral surface 84 of thefirst sealing ring 8 a is pressed against the outerperipheral surface 34 of thelower end part 33 a of therotor body 31 of therotor 3 and that of thesecond sealing ring 8 b is pressed against the outerperipheral surface 34 of theupper end part 33 b of therotor body 31 of therotor 3. Acircumferential grease groove 86 is formed in the innerperipheral surface 84, and grease is filled in thisgrease groove 86. It is onecircumferential grease groove 86 here that is formed in the innerperipheral surface 84; however, a plurality ofcircumferential grease grooves 86 may be formed in the innerperipheral surface 84. - The outer peripheral
annular part 82 of eachring peripheral surface 85 having a width t7 that is flat in the direction of thecenter axis 80 coincident with thecenter axis 20 of the circularcylindrical chamber 21 inside thecase 2. Thefirst sealing ring 8 a and thesecond sealing ring 8 b each enable resultant reduction of any change in contact area between the corresponding outerperipheral surface 85 and its counterpart surface upon being elastically deformed in the radial direction because the corresponding outerperipheral surface 85 has the width t7 that is flat in the direction of thecenter axis 80. It is noted that the outerperipheral surface 85 of thefirst sealing ring 8 a is pressed against the innerperipheral surface 220 of the through-hole 23 of the circularcylindrical chamber 21 inside thecase 2, and that of thesecond sealing ring 8 b is pressed against the innerperipheral surface 64 of the through-hole 60 in thelid 6. - Here, for each ring, the width t6 of the inner
peripheral surface 84 of the inner peripheralannular part 81 is narrower than the width t7 of the outer peripheral surface of the outer peripheral annular part 82 (t6<t7). This results in a frictional resistance of the innerperipheral surface 84 of each inner peripheralannular part 81 smaller than a frictional resistance of the outer peripheral surface of the corresponding outer peripheralannular part 82. Consequently, when therotor 3 rotates relative to the circularcylindrical chamber 21 within thecase 2, sliding occurs between the innerperipheral surface 84 with the lower friction coefficient of the inner peripheralannular part 81 and the outerperipheral surface 34 of the part against which this innerperipheral surface 84 is pressed, namely thelower end part 33 a or theupper end part 33 b of therotor body 31 of therotor 3, while the outerperipheral surface 85 with the higher friction coefficient of the outer peripheralannular part 82 remains in close contact with and without sliding on the surface against which this outerperipheral surface 85 is pressed, namely the innerperipheral surface 220 of the through-hole 23 of the circularcylindrical chamber 21 inside thecase 2 or the innerperipheral surface 64 of the through-hole 60 in thelid 6. - However, when rubber hardness of the
first sealing ring 8 a and that of thesecond sealing ring 8 b each fall within the range of 30 Shore (A) to 60 Shore (D), the ratio of the width t6 of the innerperipheral surface 84 of the corresponding inner peripheralannular part 81 to the width t7 of the outerperipheral surface 85 of the corresponding outer peripheralannular part 82 may be preferably given by t7/t6≤3. Where t7/t6>3, the width t7 of the outerperipheral surface 85 of the outer peripheralannular part 82 is too long compared to the width t6 of the innerperipheral surface 84 of the inner peripheralannular part 81; an edge part of the outerperipheral surface 85 of the outer peripheralannular part 82 becomes bent radially inward, and therefore the intended sealablity may not be provided. In addition, this may result in the need for larger installation space for thefirst sealing ring 8 a or for thesecond sealing ring 8 b. - Where rubber hardness of the
first sealing ring 8 a and that of thesecond sealing ring 8 b each fall within the range of 30 Shore (A) to 60 Shore (D), a width t9 of thegrease groove 86 provided on the innerperipheral surface 84 of the corresponding inner peripheral annular part 81 (in the case of a plurality ofgrease grooves 86 provided on the innerperipheral surface 84, t9 represents combined width of these grease grooves 86) may preferably has the following relation to the width t6 of the innerperipheral surface 84 of the corresponding inner peripheral annular part 81: 0.05≤t9/t6≤0.5. The t9/t6 less than 0.05 causes retaining amount of the lubricating grease within thegrease groove 86 to decrease, and this may result in sliding performance degradation. On the other hand, the t9/t6 greater than 0.5 causes the contact area between the inner peripheral surface of the inner peripheralannular part 81 and the surface (the outerperipheral surface 34 of thelower end part 33 a or theupper end part 33 b of therotor body 31 of the rotor 3) against which the innerperipheral surface 84 is pressed to become too small, and this may result in sealability degradation. - The
coupling part 83 is located between the inner peripheralannular part 81 and the outer peripheralannular part 82 to provide a connection between the two. Thecoupling part 83 has a width t8 (t8<t6<t7) smaller in the direction of thecenter axis 80 than both the width t6 of the inner peripheral annular part 81 (the width of the inner peripheral surface 84) and the width t7 of the outer peripheral annular part 82 (the width of the outer peripheral surface 85). When thefirst sealing ring 8 a and thesecond sealing ring 8 b each are subject to a stress, this allows the correspondingcoupling part 83 to be deformed elastically so as to absorb the stress, thereby restraining the corresponding inner peripheral annular part and the corresponding outer peripheralannular part 82 from being elastically deformed. - Here, when rubber hardness of the
first sealing ring 8 a and that of thesecond sealing ring 8 b each fall within the range of 30 Shore (A) to 60 Shore (D), the ratio of the width t8 of the correspondingcoupling part 83 to the width t6 of the corresponding inner peripheralannular part 81, may be preferably given by 0.3≤t8/t6≤0.95. The t8/t6 smaller than 0.3 causes stiffness of the correspondingcoupling part 83 to decrease, thereby allowing pressing force exerted on the outerperipheral surface 34 of thelower end part 33 a or of theupper end part 33 b of therotor body 31 of therotor 3 by the innerperipheral surface 84 of the inner peripheralannular part 81 to become too small, and this may result in sealability degradation. On the other hand, the t8/t6 greater than 0.95 causes stiffness of the correspondingcoupling part 83 to increase, thereby allowing pressing force exerted on the outerperipheral surface 34 of thelower end part 33 a or of theupper end part 33 b of therotor body 31 of therotor 3 by the inner peripheral surface of the inner peripheralannular part 81 to become too strong, and this may results in sliding performance degradation. - For the
rotary damper 1 with the structure as described above, when therotor 3 is rotationally moved in the first rotating direction R1 relative to the circularcylindrical chamber 21 inside the case 2 (SeeFIG. 2(B) ), thefirst branch 53 of thevalve seal 5 attached to each of thevanes 32 of therotor 3 is brought into contact with one side face 37 a of the correspondingvane 32, thereby closing theflow passage 36 formed through the correspondingvane 32. In the meanwhile, each of the valve seals 5 seals the gap between thefront face 35 of the correspondingvane 32 and the innerperipheral surface 24 of the circularcylindrical chamber 21 inside the case 2 (SeeFIG. 4(B) ). Consequently, movement of the viscous fluid filled within the circularcylindrical chamber 21 is only allowed through a gap g1 between thefront face 26 of each partitioningpart 25 of the circularcylindrical chamber 21 inside thecase 2 and the outerperipheral surface 34 of therotor body 31 of therotor 3, a gap g2 between anupper face 29 of each partitioningpart 25 and alower face 63 of thelid 6, a gap g3 between thelower face 63 of thelid 6 and anupper face 38 of eachvane 32 of therotor 3, and the like (SeeFIG. 3(A) andFIG. 3(B) ), thereby increasing pressure on viscous fluid in eacharea 21 a (SeeFIG. 2(B) ) partitioned by the correspondingvane 32 and the corresponding partitioningpart 25 located in the first rotating direction R1 relative to the correspondingvane 32. Therefore, a high damping torque generates. - To the contrary, when the
rotor 3 is rotationally moved in the second rotating direction R2 relative to the circularcylindrical chamber 21 inside the case 2 (SeeFIG. 2(B) ), thefirst branch 53 of thevalve seal 5 attached to each of thevanes 32 of therotor 3 moves away from one side face 37 a of the correspondingvane 32, thereby opening theflow passage 36 formed through the correspondingvane 32. Consequently, the viscous fluid filled within the circularcylindrical chamber 21 moves not only through the above gaps g1 to g3 and the like, but also through theflow passage 36 formed in each of thevanes 32, and therefore pressure on the viscous fluid within eacharea 21 b (SeeFIG. 2(B) ) partitioned by the correspondingvane 32 and the corresponding partitioningpart 25 located in the second rotating direction R2 relative to the correspondingvane 32 does not become increased as compared to that of the case of rotating therotor 3 in the first rotating direction R1 relative to the circularcylindrical chamber 21 inside thecase 2. This results in generation of a lower damping torque than that of the case of rotating therotor 3 in the first rotating direction R1 relative to the circularcylindrical chamber 21 inside thecase 2. - Hereinabove, one embodiment of the present invention has been described.
- According to the present embodiment, the
rotor 3 is slidably held by both of thefirst bushing 4 a and thesecond bushing 4 b respectively attached to the through-hole 23 of the circularcylindrical chamber 21 inside thecase 2 and the through-hole 60 in thelid 6, and therefore the misalignment of therotor 3 is suppressed even without enhancement of the stiffness of thefirst sealing ring 8 a and thesecond sealing ring 8 b which along with thefirst bushing 4 a and thesecond bushing 4 b hold therotor 3 slidable. This enables thefirst sealing ring 8 a and thesecond sealing ring 8 b to be each designed to have such low stiffness that the bothrings rotor 3, thereby resulting in no gap both between therotor 3 and thefirst sealing ring 8 a and between therotor 3 and thesecond sealing ring 8 b and in resultant decrease of the likelihood of external leakage of the viscous fluid held in the circularcylindrical chamber 21 inside thecase 2. - Furthermore, in the present embodiment, the first sealing ring 8 a is located between the through-hole 23 of the circular cylindrical chamber 21 inside the case 2 and the lower end part 33 a of the rotor body 31 of the rotor 3, and is an elastic member having the outer and inner peripheral surfaces 85, 84, namely, the outer peripheral surface 85 having the width t7 that is flat in the direction of the center axis 20 of the circular cylindrical chamber 21 and being pressed against the inner peripheral surface 220 of the through-hole 23, and the inner peripheral surface 84 having the width t6 that is flat in the direction of the center axis 20 of the circular cylindrical chamber 21 and being pressed against the outer peripheral surface 34 of the lower end part 33 a of the rotor body 31; whereas the second sealing ring 8 b is located between the through-hole 60 in the lid 6 and the upper end part 33 b of the rotor body 31, and is an elastic member having the outer and inner peripheral surfaces 85, 84, namely, the outer peripheral surface 85 having the width t7 that is flat in the center axis 20 of the circular cylindrical chamber 21 and being pressed against the inner peripheral surface 64 of the through-hole 60, and the inner peripheral surface 84 having the width t6 that is flat in the center axis 20 of the circular cylindrical chamber 21 and being pressed against the outer peripheral surface 34 of the upper end part 33 b of the rotor body 31.
- This enables resultant reduction of the changes in the following contact areas upon occurrence of misalignment of the
rotor 3 causing elastic deformation of each of the first and second sealing rings 8 a, 8 b in the radial direction, in comparison with the case of using an O-ring with a circular cross-section as an alternative to each of the first and second sealing rings 8 a, 8 b: a contact area between thefirst sealing ring 8 a and thelower end part 33 a of therotor body 31, a contact area between thefirst sealing ring 8 a and the through-hole 23 of the circularcylindrical chamber 21, a contact area between thesecond sealing ring 8 b and theupper end part 33 b of therotor body 31, and a contact area between thesecond sealing ring 8 b and the through-hole 60 in thelid 6. As a result, seal tightness between the through-hole 23 of the circularcylindrical chamber 21 and thelower end part 33 a of therotor body 31 and that between the through-hole 60 in thelid 6 and theupper end part 33 b of therotor body 31 become stable, thus further decreasing the likelihood of leakage of the viscous fluid filled within the circularcylindrical chamber 21 through the gaps therebetween. - Furthermore, according to the present embodiment, in each of the first and second sealing rings 8 a, 8 b, the width t6 of the inner
peripheral surface 84 is smaller than the width t7 of the outerperipheral surface 85. This results in a frictional resistance of each innerperipheral surface 84 smaller than a frictional resistance of the corresponding outerperipheral surface 85; rotating therotor 3 relative to the circularcylindrical chamber 21 inside thecase 2 causes sliding between each innerperipheral surface 84 with the lower friction coefficient and its corresponding counterpart surface (in case of thefirst sealing ring 8 a, the outerperipheral surface 34 of thelower end part 33 a of therotor body 31, but in case of thesecond sealing ring 8 b, the outerperipheral surface 34 of theupper end part 33 b of the rotor body 31), meanwhile each outerperipheral surface 85 with the higher friction coefficient remains in close contact with and in no sliding relative to its corresponding counterpart surface (in case of thefirst sealing ring 8 a, the innerperipheral surface 220 of the through-hole 23 of the circularcylindrical chamber 21, but in case of thesecond sealing ring 8 b, the innerperipheral surface 64 of the through-hole 60 in the lid 6). - Furthermore, according to the present embodiment, the
circumferential grease grooves 86 are formed in the innerperipheral surfaces 84 of the first and second sealing rings 8 a, 8 b, and the grease is filled in thesegrease grooves 86. Therefore, frictional resistance between each of the first and second sealing rings 8 a, 8 b and therotor 3 becomes decreased, and this enables therotor 3 to slide more smoothly. - Furthermore, in the present embodiment, the first and second sealing rings 8 a, 8 b each have the corresponding inner peripheral
annular part 81 rectangular in cross section including the innerperipheral surface 84, the corresponding outer peripheralannular part 82 rectangular in cross section including the outerperipheral surface 85, and thecorresponding coupling part 83 providing the connection between the corresponding inner peripheralannular part 81 and the corresponding outer peripheralannular part 82; in addition, thecoupling part 83 of each rings 8 a, 8 b has the width t8 which is smaller in the direction of thecenter axis 20 of the circularcylindrical chamber 21 than that of both the corresponding inner peripheralannular part 81 and the corresponding outer peripheralannular part 82. Consequently, when each of the first and second sealing rings 8 a, 8 b is subject to stress, the correspondingcoupling part 82 is elastically deformed to absorb the stress, thereby suppressing elastic deformation of the corresponding inner peripheralannular part 81 and that of the corresponding outer peripheralannular part 82 to reduce the changes in the following respective contact areas: the contact area between thefirst sealing ring 8 a and thelower end part 33 a of therotor body 31, the contact area between thefirst sealing ring 8 a and the through-hole 23 of the circularcylindrical chamber 21, the contact area between thesecond sealing ring 8 b and theupper end part 33 b of therotor body 31, and the contact area between thesecond sealing ring 8 b and the through-hole in thelid 6. Consequently, seal tightness between the through-hole 23 of the circularcylindrical chamber 21 and thelower end part 33 a of therotor body 31 and that between the through-hole 60 in thelid 6 and theupper end part 33 b of therotor body 31 become further stable, thus further decreasing the likelihood of leakage of the viscous fluid filled within the circularcylindrical chamber 21 through the gaps therebetween. - Furthermore, in the present embodiment, the
step 221 and thestep 222 are formed on the innerperipheral surface 220 of the through-hole 23 of the circular cylindrical chamber inside thecase 2 so as to respectively restrict thefirst sealing ring 8 a and thefirst bushing 4 a from moving axially outward, and thestep 340 a is formed on the outerperipheral surface 34 of thelower end part 33 a of therotor body 31 so as to restrict thefirst sealing ring 8 a and thefirst bushing 4 a, both being attached, from moving axially inward. This restricts axial movement of both thefirst sealing ring 8 a and thefirst bushing 4 a thereby achieving enhancement in seal tightness provided by thefirst sealing ring 8 a, and also stabilizes a position where thefirst bushing 4 a holds therotor 3 thereby achieving more effective reduction of misalignment of therotor 3. - In a similar way, in the present embodiment, the
step 65 and thestep 66 are formed on the inner peripheral surface of the through-hole 60 in thelid 6 so as to restrict respectively thesecond sealing ring 8 b and thesecond bushing 4 b from moving axially outward, and thestep 340 b is formed on the outerperipheral surface 34 of theupper end part 33 b of therotor body 31 so as to restrict thesecond sealing ring 8 b and thesecond bushing 4 b from moving axially inward. This restricts axial movement of both thesecond sealing ring 8 b and thesecond bushing 4 b thereby achieving enhancement in seal tightness provided by thesecond sealing ring 8 b, and also stabilizes a position where thesecond bushing 4 b holds therotor 3 thereby achieving more effective reduction of misalignment of therotor 3. - Furthermore, according to the present embodiment, because resin excellent in sliding properties, such as polyamide, is used as the material for the valve seals 5, each of the valve seals 5 acts as a slide bearing for slidable support of the outer
peripheral surface 34 of therotor body 31 of therotor 3, thereby absorbing, along with thefirst bushing 4 a and thesecond bushing 4 b, rattling due to decentering and others of the shaft for transmitting the external rotation force to therotor 3, and this causes the shaft to be rotatable smoothly. - The present invention can include, but is not limited to, the above embodiments: it will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention.
- For example, in the above embodiments, the
first bushing 4 a is located axially outside thefirst sealing ring 8 a (SeeFIG. 2(A) andFIG. 4(A) ), but not limited in this respect: thefirst bushing 4 a may be located axially inside thefirst sealing ring 8 a. Similarly, in the above embodiments, thesecond bushing 4 b is located axially outside thesecond sealing ring 8 b (SeeFIG. 2(A) ,FIG. 3(A) , andFIG. 3(B) ); however, thesecond bushing 4 b may be located axially inside thesecond sealing ring 8 b. For these cases, the circularcylindrical chamber 21 inside thecase 2 holds the viscous fluid excellent in lubricating properties, and therefore thefirst bushing 4 a and thesecond bushing 4 b are lubricated by the viscous fluid held in the circular cylindrical chamber inside thecase 2 to hold therotor 3 rotatable more smoothly. - The above embodiments use as each of the first and second sealing rings 8 a, 8 b, a member having the inner peripheral
annular part 81 having a rectangular cross-section and including the innerperipheral surface 84, the outer peripheralannular part 82 having a rectangular cross-section and including the outerperipheral surface 85, and thecoupling part 83 providing the connection between the inner peripheralannular part 81 and the outer peripheralannular part 82; however the scope of the present invention is not limited in this respect. Anything may be used as each of the first and second sealing rings 8 a, 8 b as long as it has the innerperipheral surface 84 having the width t6 in the direction of thecenter axis 20 of the circularcylindrical chamber 21 and the outerperipheral surface 85 having the width t7 in the direction of thecenter axis 20 of the circularcylindrical chamber 21. Examples of eachring peripheral surface 84 and the outerperipheral surface 85. - In the above embodiments, each of the first and second sealing rings 8 a, 8 b is designed such that the width t6 of the corresponding inner
peripheral surface 84 is smaller than the width t7 of the corresponding outerperipheral surface 85, resulting in occurrence of slide between the corresponding innerperipheral surface 84 and its counterpart surface. The scope of the present invention; however, is not limited in this respect. For example, each of the first and second sealing rings 8 a, 8 b may be designed such that the width t7 of the corresponding outerperipheral surface 85 is smaller than the width t6 of the corresponding innerperipheral surface 84, thereby enabling the corresponding outerperipheral surface 85 to slide relative to its counterpart surface. Alternatively, each of the first and second sealing rings 8 a, 8 b may be designed such that the width t6 of the corresponding innerperipheral surface 84 is about equal to the width t7 of the outerperipheral surface 85, thereby causing the innerperipheral surface 84 and the outerperipheral surface 85 to be slidable relative to the respective counterpart surfaces. - In the above embodiments, the
circumferential grease grooves 86 are formed on the innerperipheral surfaces 84 of the first and second sealing rings 8 a, 8 b, and the grease is filled in thesegrease grooves 86. The scope of the present invention, however, is not limited in this respect. As for each of the first and second sealing rings 8 a, 8 b, the circumferential grease groove(s) may be formed on at least one surface slidable to its counterpart surface, out of two surfaces that are the innerperipheral surface 84 and the outerperipheral surface 85, and grease may be filled in the grease groove(s). - In the above embodiments, the inner
peripheral surface 84 and the outerperipheral surface 85, of each of the first and second sealing rings 8 a, 8 b, are flat in the direction of thecenter axis 20 of the circularcylindrical chamber 21; however, the scope of the present invention is not limited in this respect. Any surface can be available as either the innerperipheral surface 84 or the outerperipheral surface 85, of each of the first and second sealing rings 8 a, 8 b, as far as it has a width in the direction of thecenter axis 20 of the circularcylindrical chamber 21. -
FIG. 11(A) is a front view of each of modifications 8′a, 8′b of the first and second sealing rings 8 a, 8 b,FIG. 11(B) is an I-I cross-section view of each modification 8′a, 8′b as illustrated inFIG. 11(A) , andFIG. 11(C) is an enlarged view of the part G of each modification 8′a, 8′b as illustrated inFIG. 11(B) . - These modifications 8′a, 8′b are, as with the first and second sealing rings 8 a, 8 b, annular members made of elastic material, such as nitrile butadiene rubber: the modification 8′a of the
first sealing ring 8 a has an inner diameter d1 smaller than an outer diameter d4 of thelower end part 33 a of therotor body 31 of therotor 3 and an outer diameter d2 larger than an inner diameter d3 of the through-hole 23 of the circularcylindrical chamber 21 inside the case 2 (an outer diameter of the step 221); and the modification 8′b of thesecond sealing ring 8 b has an inner diameter d1 smaller than an outer diameter d5 of theupper end part 33 b of therotor body 31 of therotor 3 and an outer diameter d2 larger than an inner diameter d6 of the through-hole 60 in the lid (an outer diameter of the step). In addition, these modifications 8′a, 8′b each have an innerperipheral surface 84′ with the width t6 in the direction of thecenter axis 80 and an outerperipheral surface 85′ with the width t7 in the direction of thecenter axis 80. Here, the width t6 of the innerperipheral surface 84′ and the width t7 of the outerperipheral surface 85′ are equal in length, but both may be different in length. - The inner
peripheral surface 84′ is a curved surface along arc having a radius r1 larger than half of a radial width t10 of the modification 8′a, 8′b in the direction of thecenter axis 80 coincident with thecenter axis 20 of the circularcylindrical chamber 21 inside the case 2: for the modification 8′a of thefirst sealing ring 8 a, the innerperipheral surface 84′ is pressed against the outerperipheral surface 34 of thelower end part 33 a of therotor body 31 of therotor 3, whereas for the modification 8′b of thesecond sealing ring 8 b, against the outerperipheral surface 34 of theupper end part 33 b of therotor body 31 of therotor 3. Similarly, the outerperipheral surface 85′ is a curved surface along an arc having a radius r2 larger than half of the radial width t10 of the modification 8′a, 8′b in the direction of thecenter axis 80; for the modification 8′a of thefirst sealing ring 8 a, the outerperipheral surface 85′ is pressed against the innerperipheral surface 220 of the through-hole 23 of the circularcylindrical chamber 21 inside thecase 2, whereas for the modification 8′b of thesecond sealing ring 8 b, against the innerperipheral surface 64 of the through-hole 60 in thelid 6. - Also for such the structure, it is possible to lessen a curvature of the inner
peripheral surface 84′ and that of the outerperipheral surface 85′ in comparison with respective curvatures of O-ring usable as alternative for each of the modifications 8′a, 8′b. This enables resultant reduction of changes in contact areas between both the innerperipheral surface 84′ and the outerperipheral surface 85′ and the respective counterpart surfaces upon deforming the modifications 8′a, 8′b elastically in the radial direction, thereby achieving enhancement in seal tightness. - The above embodiments have been described taking the example in which the circular
cylindrical chamber 21 is provided with the pair of thepartitioning parts 25 and therotor 3 is provided with the pair of thevanes 32. The scope of the present invention, however, is not limited in this respect. As far as the partitioning part(s) 25 formed in the circularcylindrical chamber 21 and the vane(s) 32 formed on therotor 3 are the same in number, the numbers of the partitioning part(s) 25 and the vane(s) 32 each may be one, three, or more. - In the above embodiments, the
valve seal 5 attached to eachvane 32 serves as a check valve for opening and closing theflow passage 36 formed through the correspondingvane 32, but the scope of the present invention is not limited in this respect. In addition to the valve seals 5, check valves may be used which close theflow passages 36 formed in therespective vanes 32 on rotating therotor 3 in the first rotating direction R1 relative to the circularcylindrical chamber 21 and which open theflow passages 36 formed in therespective vanes 32 on rotating therotor 3 in the second rotating direction R2 relative to the circularcylindrical chamber 21. - In the above embodiments, the
flow passages 36 are each formed in the correspondingvane 32 along the rotation direction of therotor 3 so as to pass through the both side faces 37 a, 37 b of the correspondingvane 32, but the scope of the present invention is not limited in this respect. In thepartitioning parts 25 instead of thevanes 32 or not only in thevanes 32 but also in thepartitioning parts 25, such flow passages may be formed along the rotation direction of therotor 3. In this case, check valves may be installed which close the respective flow passages formed in thepartitioning parts 25 upon rotating therotor 3 in the first rotating direction R1 relative to the circularcylindrical chamber 21 and open the respective flow passages formed in thepartitioning parts 25 upon rotating the rotor in the second rotating direction R2 relative to the circularcylindrical chamber 21. - It is noted that when the flow passages are formed in the
partitioning part 25, thepartitioning parts 25 may each have a seal member attached thereto to serve similarly to thevalve seal 5, that is, a seal member including a bottom part having a width longer than a circumferential directional width of an inner peripheral edge of the corresponding partitioningpart 25, a first branch formed integrally with one edge of the bottom part and having a width longer than a radial directional width of the flow passage formed through the corresponding partitioningpart 25, and a second branch formed integrally with another edge of the bottom part and having a width shorter than a radial directional width of the flow passage formed in the corresponding partitioningpart 25.Rotating rotor 3 in the first rotating direction R1 relative to the circularcylindrical chamber 21 causes each of the seal members to bring the first branch into contact with one side of the corresponding partitioningpart 25, thereby closing the flow passage formed in each of thepartitioning parts 25, and conversely rotating therotor 3 in the second rotating direction R2 relative to the circularcylindrical chamber 21 causes each of the seal member to move the first branch away from one side of the corresponding partitioningpart 25 and to bring the second branch into contact with another side of the corresponding partitioningpart 25, thereby opening the flow passage formed in each of thepartitioning parts 25. - If the
flow passage 36 is not formed in thevane 32, the correspondingvalve seal 5 may have any shape as long as it can close the gap between thefront face 35 of thevane 32 and the innerperipheral surface 24 of the circularcylindrical chamber 21. Alternatively, thevalve seal 5 may be omitted. - In the above embodiments, the internal threaded
section 27 is formed on theopening side 28 of the innerperipheral surface 24 of the circularcylindrical chamber 21, the external threadedsection 62 is formed on the outerperipheral surface 61 of thelid 6 so as to be screwed into this internal threadedsection 27, and thelid 6 is thereby fixed to thecase 2. The scope of the present invention, however, is not limited in this respect. Thelid 6 may be fixed to thecase 2, for example, by bolts or by rivets. Alternatively, thelid 6 and thecase 2 may be joined by joining way, such as gluing or welding. - In the above embodiments, the external rotation force is applied to the
rotor 3, thus rotating therotor 3 relative to the circularcylindrical chamber 21 inside thecase 2. The scope of the present invention, however, is not limited in this respect. Applying the external rotation force to thecase 2 may rotate therotor 3 relative to the circularcylindrical chamber 21 inside thecase 2. - The above embodiments have been described taking the example of the so-called uni-directional
rotary damper 1 in which rotating therotor 3 in the first rotating direction R1 relative to the circularcylindrical chamber 21 causes a higher damping torque than if rotating therotor 3 in the second rotating direction R2 relative to the circularcylindrical chamber 21. The scope of the present invention, however, is not limited in this respect. The present invention may be applied to any so-called bi-directional rotary damper that can work in both the first rotating direction R1 and the second rotating direction R2 so as to cause a damping torque depending on the resistance to motion of the viscous fluid passing through the flow passage formed in each of thevanes 32 or in each of the partitioning parts (the degree to which the viscous fluid is hard to be moved through the flow passage). For this case, thevalve seal 5 may not necessarily need to serve as a check valve. Thevalve seal 5 may be anything as long as it can fill the gap between thefront face 35 of the correspondingvane 32 and the innerperipheral surface 24 of the circularcylindrical chamber 21. Alternatively, thevalve seal 5 may be omitted. - The above embodiment has been described taking the example of the
rotary damper 1 that generates the damping torque in reaction to the external rotation force by limiting movement of the viscous fluid. The present invention can include, but is not limited to, the above embodiment. The present invention can be widely applied to any damper that generates a damping force in reaction to an external force by limiting a movement of viscous fluid. -
FIG. 12(A) is a side view of alinear type damper 9 according to another embodiment of the present invention, andFIG. 12(B) is a J-J cross-section view of the linear type damper as illustrated inFIG. 12(A) . - The
linear type damper 9 according to the present embodiment is available for any device in which a linear motion of a moving object is to be damped, such as seats with height adjustment function and movable shelves. As illustrated in the figures, thelinear type damper 9 has the following: acase 920 and alid 960 that form the fluid holding chamber holding the viscous fluid (not illustrated in the figures), such as oil or silicone; and ashaft 930 housed in the fluid holding chamber so as to be linearly movable relative to the fluid holding chamber in a direction of acenter axis 902. - A circular
cylindrical chamber 921 with one end open (i.e. a space having a circular cylindrical shape with a bottom) is formed inside of thecase 920, and aninsertion hole 923 for insertion of theshaft 930 is formed in abottom part 922 of this circularcylindrical chamber 921. Afirst sealing ring 980 a and afirst bushing 990 a are attached to thisinsertion hole 923, and then the insertion of oneend part 933 a of a below-mentionedshaft body 931 into theinsertion hole 923 having thesefirst sealing ring 980 a andfirst bushing 990 a attached thereto places theshaft 930 in the circularcylindrical chamber 921 so as to align acenter axis 903 of theshaft 930 with thecenter axis 902 of the circularcylindrical chamber 921. - A mounting
section 927 for attachment of thefirst sealing ring 980 a and thefirst bushing 990 a is formed in an innerperipheral surface 929 of theinsertion hole 923 to be in a stepped annular groove shape. A through-hole 926 for air vent is formed through abottom part 925 inside theinsertion hole 923. Thelid 960 is fixed onto theopening side 928 of an innerperipheral surface 924 of the circularcylindrical chamber 921 by jointing way, such as threaded joint, gluing, welding, fastening with a screw, and fastening with a machine screw. - The
shaft 930 includes theshaft body 931 in a substantial cylindrical shape and aflange 932 formed near or at the middle of length of theshaft body 931. - The
flange 932 projects, near or at the middle of length of theshaft body 931, radially outward from an outerperipheral surface 934 of theshaft body 931 so as to place itsfront face 935 close to the innerperipheral surface 924 of the circularcylindrical chamber 921 inside thecase 920, thereby partitioning the inside of the circularcylindrical chamber 921. Theflange 932 forms volume changing means to compress one area and expand another area within the circularcylindrical chamber 921 partitioned by theflange 932 according to linear motion in a direction along thecenter axis 903 of theshaft 930. In theflange 932, flowpassages 936 are formed along the direction of thecenter axis 903 of theshaft 930 so as to pass through both side face 937 a, 937 b of theflange 932. Checkvalves 970 are installed in therespective flow passages 936 so as to close therespective flow passages 936 in case of moving theshaft 930, along thecenter axis 902 of the circularcylindrical chamber 921, in a first moving direction L1, and so as to open therespective flow passages 936 in another case of moving theshaft 930 in a second moving direction L2, namely, a direction opposite to the first moving direction L1. A gap g′ is formed between the outerperipheral surface 935 of theflange 932 and the innerperipheral surface 924 of the circularcylindrical chamber 921 inside thecase 920 so as to work as a flow passage for the viscous fluid filled within the circularcylindrical chamber 921. - The
shaft body 931 serves as a resistance generating member capable of moving in the direction of thecenter axis 902 of the circularcylindrical chamber 921 relative to the circularcylindrical chamber 921 in reaction to the external force in the direction of thecenter axis 903 of theshaft 930. For theshaft body 931, oneend part 933 a is to be inserted into theinsertion hole 923 formed in thebottom part 922 of the circularcylindrical chamber 921 inside thecase 920 so as to be movable in the direction of thecenter axis 902 of the circularcylindrical chamber 921, whereas anotherend part 933 b is to be inserted into a through-hole 961 in thelid 960 so as to be movable in the direction of thecenter axis 902 of the circularcylindrical chamber 921. - In the
lid 960, the through-hole 961 for insertion of theshaft 930, which serves as the opening section of the fluid holding chamber, is formed at a place opposite to theinsertion hole 923 formed in thebottom part 922 of the circularcylindrical chamber 921 inside thecase 920. Asecond sealing ring 980 b and asecond bushing 990 b are attached to this through-hole 961, anotherend part 933 b of theshaft body 931 of theshaft 930 is inserted into the through-hole 961 to which thesesecond sealing ring 980 b andsecond bushing 990 b are attached. Moreover, a mountingsection 962 for attachment of thesecond sealing ring 980 b and thesecond bushing 990 b is formed in an innerperipheral surface 964 of the through-hole 961 to be in a stepped annular groove shape. - The
first bushing 990 a and thesecond bushing 990 b are each a cylindrical member made of material excellent in sliding properties: thefirst bushing 990 a has an inner peripheral surface slidable to the outerperipheral surface 934 of theshaft body 931 of theshaft 930 and an outer peripheral surface to abut the innerperipheral surface 929 of theinsertion hole 923 of the circularcylindrical chamber 921 inside thecase 920; and thesecond bushing 990 b has an inner peripheral surface slidable to the outerperipheral surface 934 of theshaft body 931 of theshaft 930 and an outer peripheral surface to abut the innerperipheral surface 964 of the through-hole 961 in thelid 960. - The
first bushing 990 a and thesecond bushing 990 b may each be made of metal, such as brass alloy, or synthetic resin, such as PTFE, polyacetal resin, polyethylene resin, polyamide resin, and polyphenylene sulfide resin. Alternatively, thefirst bushing 990 a and thesecond bushing 990 b may each be made of such multi-layer sliding material that on an inner peripheral surface of a backing material in a cylindrical shape are formed a plurality of sliding layers each including a woven or a non-woven fabric impregnated with synthetic resin, such as phenolic resin. - The first and second sealing rings 980 a, 980 b are each an annular member made of elastic material, such as nitrile butadiene rubber. The
first sealing ring 980 a includes an inner peripheral surface having a width in the direction of thecenter axis 902 of the circularcylindrical chamber 921 and being slidably pressed against the outerperipheral surface 934 of theshaft body 931 and an outer peripheral surface having a width in the direction of thecenter axis 902 of the circularcylindrical chamber 921 and being pressed against a groove bottom inside the mountingsection 927 formed in the innerperipheral surface 929 of theinsertion hole 923 of thecase 920. Thesecond sealing ring 980 b includes an inner peripheral surface having a width in the direction of thecenter axis 902 of the circularcylindrical chamber 921 and being slidably pressed against the outerperipheral surface 934 of theshaft body 931 and an outer peripheral surface having a width in the direction of thecenter axis 902 of the circularcylindrical chamber 921 and being pressed against a groove bottom inside the mountingsection 962 formed in the innerperipheral surface 964 of the through-hole 961 in thelid 960. Here, the first and second sealing rings 980 a, 980 b may respectively be the first and second sealing rings 8 a, 8 b as illustrated inFIG. 10 or be the modifications 8′a, 8′b of the first and second sealing rings 8 a, 8 b as illustrated inFIG. 11 , for example. - For the
linear type damper 9 with the structure as described above, when the external force on theshaft 930 or on thecase 920 moves theshaft 930 linearly in the first moving direction L1 relative to the circularcylindrical chamber 921 inside thecase 920, thecheck valves 970 close therespective flow passages 936. Consequently, movement of the viscous fluid filled within the circularcylindrical chamber 921 is only allowed through the gap g′ between the outerperipheral surface 935 of theflange 932 of theshaft 930 and the innerperipheral surface 924 of the circularcylindrical chamber 921, thereby increasing pressure on the viscous fluid within anarea 921 a located in the first moving direction L1 relative to theflange 932. Therefore, a high damping torque generates. - To the contrary, when the external force on the
shaft 930 or thecase 920 moves theshaft 930 linearly in the second moving direction L2 relative to the circularcylindrical chamber 921 inside thecase 920, thecheck valves 970 open therespective flow passages 936. Consequently, the viscous fluid filled within the circularcylindrical chamber 921 moves not only through the gap g′ between the outerperipheral surface 935 of theflange 932 and the innerperipheral surface 924 of the circularcylindrical chamber 921 but also through theflow passages 936 formed in theflange 932, and therefore pressure on the viscous fluid within anarea 921 b located in the second moving direction L2 relative to theflange 932 does not become increased as compared to that of the case of moving theshaft 930 in the first moving direction L1 relative to the circularcylindrical chamber 921 inside thecase 920. This results in generation of a lower damping torque than that of the case of rotating theshaft 930 in the first moving direction L1 relative to the circularcylindrical chamber 921 inside thecase 920. - The
linear type damper 9 with the structure as described above also achieves an advantage similar to that of therotary damper 1 as illustrated inFIG. 1 . Namely, for thelinear type damper 9, theshaft 930 is slidably held by both thefirst bushing 990 a and thesecond bushing 990 b respectively attached to theinsertion hole 923 of the circularcylindrical chamber 921 inside thecase 920 and the through-hole 961 in thelid 960, and therefore the misalignment of theshaft 930 is suppressed even without enhancement of the stiffness of thefirst sealing ring 980 a and thesecond sealing ring 980 b which along with thefirst bushing 990 a and thesecond bushing 990 b hold theshaft 930 slidable. This enables thefirst sealing ring 980 a and thesecond sealing ring 980 b to be each designed to have such low stiffness that the bothrings shaft 930, thereby resulting in no gap between theshaft 930 and both thefirst sealing ring 980 a and thesecond sealing ring 980 b and in resultant decrease of the likelihood of external leakage of the viscous fluid held within the circularcylindrical chamber 921 inside thecase 920. - Moreover, in the linear type damper 9, the first sealing ring 980 a is located between the insertion hole 923 of the circular cylindrical chamber 921 inside the case 920 and one end part 933 a of the shaft body 931 of the shaft 930, and the second sealing ring 980 b is located between the through-hole 961 in the lid 960 and another end part 933 b of the shaft body 931: the first sealing ring 980 a includes an inner peripheral surface having the width that is flat in the direction of the center axis 902 of the circular cylindrical chamber 921 and being slidably pressed against the outer peripheral surface 934 of the shaft body 931 and an outer peripheral surface having the width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being pressed against the groove bottom inside the mounting section 927 formed in the inner peripheral surface 929 of the insertion hole 923 of the case 920, and the second sealing ring 980 b includes an inner peripheral surface having the width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being slidably pressed against the outer peripheral surface 934 of the shaft body 931 and an outer peripheral surface having the width in the direction of the center axis 902 of the circular cylindrical chamber 921 and being pressed against the groove bottom inside the mounting section 962 formed in the inner peripheral surface 964 of the through-hole 961 in the lid 960.
- This enables resultant reduction of the changes in the following contact areas upon occurrence of misalignment of the
shaft 930 causing elastic deformation of each of the first and second sealing rings 980 a, 980 b in the radial direction, in comparison with the case of using an O-ring with a circular cross-section as an alternative to each of the first and second sealing rings 980 a, 980 b: a contact area between thefirst sealing ring 980 a and oneend part 933 a of theshaft body 931, a contact area between thefirst sealing ring 980 a and the groove bottom inside the mountingsection 927 formed in theinsertion hole 923 of the circularcylindrical chamber 921, a contact area between thesecond sealing ring 980 b and anotherend part 933 b of theshaft body 931, and a contact area between thesecond sealing ring 980 b and the groove bottom inside the mountingsection 962 formed in the through-hole 961 in thelid 960. As a result, seal tightness between theinsertion hole 923 of the circularcylindrical chamber 921 and oneend part 933 a of theshaft body 931 and that between the through-hole 961 in thelid 960 and anotherend part 933 b of theshaft body 931 become stable, thus decreasing the likelihood of leakage of the viscous fluid filled within the circularcylindrical chamber 921 through the gaps therebetween. - 1: rotary damper; 2,920: case; 3: rotor; 4 a,990 a: first bushing; 4 b,990 b: second bushing; 5: valve seal; 6,960: lid; 7: O-ring; 8 a,980 a: first sealing ring; 8 b,980 b: second sealing ring; 9: linear type damper; 21,921: circular cylindrical chamber; 22: bottom part of the circular cylindrical chamber 21; 23: through-hole of the circular cylindrical chamber 21; 24: inner peripheral surface of the circular cylindrical chamber 21; 25: partitioning part; 26: front face of the partitioning part 25; 27: internal threaded section; 28: opening side of the circular cylindrical chamber 21; 29: upper face of the partitioning part 25; 31: rotor body; 32: vane; 33 a: lower end part of the rotor body 31; 33 b: upper end part of the rotor body 31; 34: outer peripheral surface of the rotor body 31; 35: front face of the vane 32; 36,936: flow passage; 37 a,37 b: both side faces of the vane 32; 38: insertion hole of the rotor body 31; 39: upper face of the vane 32; 40 a: inner peripheral surface of the first bushing 4 a; 40 b: inner peripheral surface of the second bushing 4 b; 41 a: outer peripheral surface of the first bushing 4 a; 41 b: outer peripheral surface of the second bushing 4 b; 50: bottom part of the valve seal 5; 51,52: edge of the bottom part 50 of the valve seal 5; 53: first branch of the valve seal 5; 54: second branch of the valve seal 5; 60: through-hole in the lid 6; 61: outer peripheral surface of the lid 6; 62: external threaded section; 63: lower face of the lid 6; 64: inner peripheral surface of the through-hole 60; 65,66: step of the inner peripheral surface 64; 67: groove of the lid 6; 81: inner peripheral annular part; 82: outer peripheral annular part; 83: coupling part; 84: inner peripheral surface of the inner peripheral annular part 81; 85: outer peripheral surface of the outer peripheral annular part 82; 86: grease groove; 220: inner peripheral surface of the through-hole 23; 221,222: step on the inner peripheral surface 220; 340 a: step of the outer peripheral surface 34 of the lower end part 33 a; 340 b: step on the outer peripheral surface 34 of the upper end part 33 b; 922: bottom part of the circular cylindrical chamber 921; 923: insertion hole; 924: inner peripheral surface of the circular cylindrical chamber 921; 925: bottom part inside the insertion hole 923; 926: through-hole for air vent; 927: mounting section for the first sealing ring 980 a; 928: opening side of the circular cylindrical chamber 921; 929: inner peripheral surface of the insertion hole 923; 930: shaft; 931: shaft body; 932: flange; 933 a, 933 b: both end parts of the shaft body 931; 934: outer peripheral surface of the shaft body 931; 935: outer peripheral surface of the flange 932; 937 a,937 b: both side faces of the flange 932; 961: through-hole in the lid 960; 962: mounting section for the second sealing ring 980 b; 964: inner peripheral surface of the through-hole 961; 970: check valve
Claims (21)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017236004A JP7075749B2 (en) | 2017-12-08 | 2017-12-08 | damper |
JP2017-236004 | 2017-12-08 | ||
JPJP2017-236004 | 2017-12-08 | ||
PCT/JP2018/043017 WO2019111714A1 (en) | 2017-12-08 | 2018-11-21 | Damper |
Publications (2)
Publication Number | Publication Date |
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US20200318706A1 true US20200318706A1 (en) | 2020-10-08 |
US11287008B2 US11287008B2 (en) | 2022-03-29 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US16/769,629 Active US11287008B2 (en) | 2017-12-08 | 2018-11-21 | Damper |
Country Status (5)
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US (1) | US11287008B2 (en) |
EP (1) | EP3722634B1 (en) |
JP (1) | JP7075749B2 (en) |
CN (1) | CN111433487B (en) |
WO (1) | WO2019111714A1 (en) |
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JP7346132B2 (en) * | 2019-07-29 | 2023-09-19 | ニデックインスツルメンツ株式会社 | fluid damper device |
JP7391823B2 (en) * | 2020-11-19 | 2023-12-05 | オイレス工業株式会社 | rotary damper |
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JPS59196738U (en) * | 1983-06-16 | 1984-12-27 | トヨタ自動車株式会社 | buffer |
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-
2017
- 2017-12-08 JP JP2017236004A patent/JP7075749B2/en active Active
-
2018
- 2018-11-21 WO PCT/JP2018/043017 patent/WO2019111714A1/en unknown
- 2018-11-21 CN CN201880078131.8A patent/CN111433487B/en active Active
- 2018-11-21 EP EP18886288.2A patent/EP3722634B1/en active Active
- 2018-11-21 US US16/769,629 patent/US11287008B2/en active Active
Also Published As
Publication number | Publication date |
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JP2019100532A (en) | 2019-06-24 |
WO2019111714A1 (en) | 2019-06-13 |
EP3722634A4 (en) | 2021-10-13 |
CN111433487B (en) | 2022-05-17 |
EP3722634B1 (en) | 2023-08-23 |
CN111433487A (en) | 2020-07-17 |
US11287008B2 (en) | 2022-03-29 |
JP7075749B2 (en) | 2022-05-26 |
EP3722634A1 (en) | 2020-10-14 |
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